If you want to play PS2 games, get a PS2 with the $100 you save on getting the 40 gig model, or spend the extra $100 and get a PS3 model that does offer BC.
I just placed my preorder for a 40 gig PS3 on Amazon. $399 plus free shipping and no sales tax. The only downside is that I will have to wait for it to be shipped, but I'm not worried about that. Plus I get Spiderman 3 on BluRay and I get 5 more free BluRay discs. Not too bad at all for $400.
I also don't think there are too many 60 gig models left, and some people will still buy them at the current price, just because it has the Emotion Engine for BC, so to some people it will be worth the extra money.