Exactly - although I think at some point the amount of memory you have doesn't make too much of a difference (especially if you have 4GB).
But yes, it's very likely Blizzard will support them and they should run fine (note that WoW, for example, runs on a very wide range of hardware, and even runs ok on integrated graphics like Intel GMA950, which is pretty low-end).
With a game like SC2 that is going to be so popular, Blizzard is certainly going to want to make sure it runs on a wide variety of hardware - again, note that the GeForce 6600 (and the Radeon 9800) which they list as the minimum requirement for the beta is a very old card....... again, I don't know what the direct benchmarks are, but I'm pretty sure the GT320M will beat them pretty handily).
-Zadillo