Is there any difference in getting a 320MB 8800GTS vs. a 640MB 8800GTS @ 1650x1080? If so, is it worth the ~$100 extra? I eventually am going to get a 1920x1200 LCD, does this change anything performance wise for the two different cards?

I would go for the 640mb version, especially if you'll be getting a bigger monitor.

100$? That sucks..

But yeh, 1920x1200 virtually NEEDS the memory.

I agree with prozac and Track on this. 1920x1200 will almost demand the upgrade in memory and you will be glad you spent the extra 100.

~BUMP~
Yeah buy the 640 or wait for HD2900XT. Personally the HD2900 would be my choice (and that's coming from a hard-core Nvidia Fanboy) but whatever way you go, don't get the 320MB. My 8800 320 runs really great, but if it ever runs out of texture RAM (such as in STALKER or Oblivion) it stops cold to load more textures. Very disappointing if you ask me.

Thanks all. My 7600GT just can't handle Lord of the Rings Online above medium @ 1680x1050. It looks amazing, but I slow down to nothing when theres a lot of action on the screen. I think I will wait until the middle or end of May to see what ATI does before I make a final decision. But thanks again.