If...
Apple announced an i3 13-inch MBP with Sandy-Bridge graphics today, I would run, not walk, to buy a 2010 MBP on clearance. Why? With all due respect to Anand LAl Shimpi and his early benchmarks, Intel has a terrible record with 3D performance in particular and graphics performance in general. Even if framerates are there, there is bound to be tearing, clipping, and other distracting artifacts. Their *nix drivers are even worse - just ask anyone who has tried to get Flash working usably with an Intel GPU under Linux (or any other non-Windows OS). Heck; my wife can't even play Farmville full-screen with her Intel GPU, let alone a 3D game. Compared with the major GPU manufacturers, Intel issues driver refreshes approximately never (basically when the hardware changes - maybe once in-between). Besides, i3 + Intel IGP is $300 netbook territory, in terms of hardware.
If they announced an i5 13-inch MBP with Intel-only graphics, I'd wait for some other kool-aid drinkers to buy the thing and benchmark it before jumping in - maybe the i5 would partly make up for the crappy GPU. Meanwhile, I'd hope for enough outcry to force Apple into putting the "pro" back into the 13-inch MBP by offering a refresh with a better GPU.
If they ditch the Optical in favor of a Sandy Bridge + discrete graphics offering, I'm all over it. I can get an external drive for the instances when I need one. Oh, and 1440 X 900, PLEASE!
I have a MBP 15-inch at work and I love it, but the way Apple seems to be headed with the 13-inch (which is the form-factor I really want), I may just stick an SSD in my current (Windows) laptop and call it good.