Well on my GMA950 I could run on mediumish with a very good framerate at 1280x800, and that's with 1GB of ram.
The X3100 can probably run at high then, yeah. Especially if you bump up your ram to 2GB, hell might run great at high settings with 4GB even. Would like to hear how it runs with 4GB of ram.
I'm sooooo burned out from WoW though.