Do you think the 660 will still max some games if I ever make the jump to 1900x1080?
Right now I can get a PNY card for $180+a code for Borderlands 2 (which is a $60 game in Steam) where I live.
I was also wondering if the squirrel cage fans are more dust-proof than the standard ones. I'm getting a CM Elite 371 case since I got a modular psu (Antec High Current Gamer HCG-520m) and a budget cpu (i3 2100), so the GPU will be my far the hottest thing inside of my case. Do you think I'll be fine with just one exhaust fan? Or should I place one intake on the side panel?
There is no such thing as "too much" power for resolution. I have an HD 6850 for a display with same res (1440x900-Asus 19") and it does struggle with Metro 2033, Skyrim, and all kinds of games that are either too tough or badly coded. GTA IV lags because it needs more cores, but that's another story...
You should get something that's a bit overkill for now and still sufficient if you go 1080p or higher. The GTX 660 or the HD 7870 would both do a great job