I don't have it (yet), but it surely will run. However I'd suggest you do yourself a favor and upgrade the gfx card to the 8800. You can order the 2,8 ghz iMac with it too.
it will run, but not with all settings 'high'
I've done some testing with all the settings on a 2.66 (and rest the same)
If you want to run it in 'high' you will get a 10-30fps (depending on environment/location) and this is terrible to play...
Switching settings to 'Off' or 'Low' and/or lower the resolution will give a performance boost to 50-75 fps to 125fps, but you give up the nice environment (as in all the screen shots on the web)