Well you're right, that's the point. 1,000 is clearly too many IMO. Those who play (or are invited to play) at the top tournaments year round are the world class players... again IMO. Perhaps you could extend it as far as the national teams of each nation... likely established GMs.
Taken in the context of the OP's post, his definition really could mean anything and it woudln't hardly surprise me.
It would be very interesting to hear from some FMs about how the preceive that gap between themselves and top IMs and Gms
I know an FM who said that a GM is someone who plays every day like he does on a good day.
As an NM myself, I find that a bit of a stretch (to put it mildly).
I feel that I am in the same ballpark with FMs (indeed, I did fairly well against them on my old account). But IMs are definitely a big step above me, and GMs are another leap above that (not that I ever got the chance to play more than a handful of those...but even so, the point was made clear enough).
It's a sure sign that the term "world class" has become totally useless when it's only useful as a term of contempt, as if it were a mortal insult to point out that a player isn't "world class." My hat is off to anyone who's achieved an FM title. They're obviously terrific players. By the same token, I'm in awe of anyone who plays scratch golf--that is, with no handicap. If you've ever played with a scratch golfer you can't believe how hard and straight they hit the ball, how delicate their touch is around the greens. But a scratch golfer would starve to death on the PGA Tour.
! (this quote says it all)
I'm a world class former chess expert
Way back when I was once a Candidate Expert. 
Just something I came across this morning from the web that may be relevant. Note that some of these players obtained their GM titles at an advanced age. Mastering chess while young is surely easier, but it doesn't mean that it cannot be done if you start late.
Joseph Henry Blackburne (1841-1924) played chess until he died at the age of 82. He tied for 1st place in the British championship at the age of 72
Grandmaster David Bronstein was playing chess in his 80s.
Arthur Dake (1910-2000) was the oldest competitive grandmaster in history. He was still playing in international master tournaments in his 80s.
Harlow Daly (1883-1979) played chess for over 75 years. He died at the age of 95. He won the championship of Maine at the age of 77, 81, and 85. He was still playing chess in his 90s.
Arnold Denker (1914-2005) died at the age of 90. He was active in chess until his late 80s.
Gisela Gresser (1906-2000) won the U.S. Women's Championship at the age of 63. She died at the age of 94.
James Hanham (1840-1923) played master level chess until he died at the age of 84.
Rea Hayes (1915-2001) played chess in his 80s. In 1998, at the age of 83,he was the oldest player in the U.S. Senior Championship. He won the Tennessee State championship at the age of 76.
Kirk Holland (1911- ), age 94, is still playing in chess tournaments in Chicago
Mona Karff (1914-1998) won the U.S. Women's Championship at the age of 60. She died at the age of 83.
George Koltanowski (1903-2000) died at the age of 96. He was a chess editor for the San Francisco Chronicle for 52 years. He became a Grandmaster at the age of 85. He was still playing blindfold chess in his 70s.
Edward Lasker (1885-1981) was playing chess until he died at the age of 95. He was still playing correspondence games when he died. He became an International Master at the age of 75.
Emanuel Lasker (1868-1941) played chess until he died at the age of 73. At the age of 68, he took 6th place in the Moscow Intenational tournament.
Alina Markowski (1910- ) is still playing chess in San Diego in her 90s. She started playing postal chess at the age of 61. She now has a chess club named after her.
Jacquest Mieses (1965-1954) died at the age of 89. He was still giving simultaneous chess exhibitions in his mid 80s. He became a grandmaster at the age of 85.
Mario Monticelli (1902-1995) was awarded the Grandmaster title at the age of 83. He died at the age of 93.
Jared Moore (1893-1995) lived until the age of 101. He was still active in postal chess until he was 100 years old. He started playing postal chess at the age of 67.
Walter Muir (1905-1999) played postal chess until he died at the age of 95. In 1997, he wrote his autobiography, My 75 Year Chess Career.
Miguel Najdorf (1910-1997) played chess until he died at the age of 87. At the age of 81, he played in the Artentina chess championship. At the age of 82, he played in the strong Mar del Plata open.
Enrico Paoli (1908-2005) became a grandmaster at the age of 88. He was the strongest active nonagenarian in the world, still playing chess at the age of 97. He died less than a month away from his 98th birthday.
Edith Price (1872-1956) won the British Women's Championship at the age of 76. She was still running her chess club, the Gambit Chess Room in England, while in her 80s.
Samuel Reshevsky (1911-1992) was still playing chess until he died at the age of 81. At the age of 70, he took 3rd place in the U.S. Championship. At the age of 72, he won a grandmaster tournament, held in Iceland.
Oscar Shapiro (1924-2004) was the oldest person to first make chess master. He became a chess master at the age of 74.
Viktor Korchnoi (1931- ) is still playing grandmaster level chess at the age of 75. He is currently the oldest grandmaster on the world chess tournament circuit. In 2005, he was still ranked in the top 100 in the world at the age of 74.
You should have added that this came from Bill Wall.
And is a bit of a wall itself...
The title says nothing,there are many IM's with an higher rating than some GM's.
The best player in the Netherlands is Giri and iam proud that he is playing for the Netherlands.
Well, let's just say that the title doesn't say everything... 
I play against an IM and won in a simul and a draw in Rapid.My rating is probaly 600 elo lower maybe more.Every player must let it see on the board and also titleholders are human.
lol...sure, whatever you say...
Just something I came across this morning from the web that may be relevant. Note that some of these players obtained their GM titles at an advanced age. Mastering chess while young is surely easier, but it doesn't mean that it cannot be done if you start late.
Kirk Holland (1911- ), age 94, is still playing in chess tournaments in Chicago
Jacquest Mieses (1965-1954) died at the age of 89. He was still giving simultaneous chess exhibitions in his mid 80s. He became a grandmaster at the age of 85.
You should have added that this came from Bill Wall.
And that you suck at maths - Kirk Holland (1911- ), age 94
And Mieses got his GM title when he was 85 because that is when the GM title was introduced (1950). It didn't exist before then.
And I should add that Andrew Martin is a chump whose instructional dvds are not very instructive at all, as he just reads lines from Chessbase even if they are incredibly inaccurate.
I agree with him, there are a lot of 'how can I become a GM?' posts on chess.com and the persons ratings haven't changed much from 3 years previous, at least in part due to their unrealistic expectations.
"
We have many world class chess players who still play strongly at such an advanced age. Smyslov, Yusupov, Lasker, and Karpov are just some of them. I am pretty sure that Kasparov can still kick all of our butts. Chess is not a physical sport, so the effect of age is not that significant. In fact, I think older people tend to have more time in their hands and thus more time to devote to chess, compared to us youngsters who still have to juggle with work, wife, young children, etc."
You miss the fact they were world class before they became old, and got worse, not better.
Andrew Martin gave this man an honest, if slightly blunt answer. But his tone was neither impolite nor condescending...
Sugarcoating is not helping people, so I don't understand why all this Martin's bashing in the thread ?! 
And I should add that Andrew Martin is a chump whose instructional dvds are not very instructive at all, as he just reads lines from Chessbase even if they are incredibly inaccurate.
Which DVDs in particular?
As a 60 year old tournament player I agree with Andrew Martin. As one gets older improving ones game becomes exponentialy more difficult. I see many beginners claim that in a few years they will be Experts and/or Masters but the only ones I ever see that are successful in doing so are quite young. One only needs to use chessbase to generate ratings graphs of rating versus age and one can see just how unusual it is for one's rating to go up as one gets up in years. Meanwhile I have played against young children who seem to be hundreds of points higher every time I play them. I lost a game last year to an eight year old who became an expert at eight and before the age of nine years and four months had already beaten a Grandmaster.
And I should add that Andrew Martin is a chump whose instructional dvds are not very instructive at all, as he just reads lines from Chessbase even if they are incredibly inaccurate.
Which DVDs in particular?
Foxy Openings 80 and 119 spring to mind immediately. For example, one position he says is good for white which could have occurred in the game Ginzburg-Zarnicki, 2002; however it is completely lost and white would in fact do well not to lose a piece.
I am sure he is a good chess player, but it is obvious that he has just opened the game on Chessbase and plays through the lines.
World class means among the best in the world... there's really no other way to interpret it...
Yes but ... best 10, best 100, best 1000? Seems still quite subjective to me.
But I agree that the notion is widely used to denote the handful of top experts on a given subject.