I haven't really looked at this in detail, but my first instinct is to play 3...e5!, attacking the d-pawn and uncovering the Bf8. I also believe that this will seize the intiative (white will be forced to defend the d4 pawn or capture the e5. If dxe5, then simply Bxc5) Edit: lol began to post at same time as tonydal so didn't see it...
I am guessing that this may be the reason why an experienced player as white doesn't commit to playing c5 so early. The only line that I know white only plays c5 is the Chebanko (sp?) Slav where black has played a6.
I've come across this a couple of times and I don't know what to do.
What's this called and what are some plans black can use? Should black bother trying to undermine white's pawn structure around c5?