2 gigs of ram, at good timings will do well for crysis. Everything else is very good, but if you want to run it on the high settings you would want to upgrade to an 8 series graphics card. But i would wait till crysis comes out for this, as prices will drop and performance will increase.
As for the RAM, its very cheap now (due to excess supply for the Vista release) so it might be a good idea to get that now, as prices will probably increase again.