Yeah, I've got a Geforce 7800 GTX with 1GB video ram, which is IIRC, 1 model below the "cutoff" so I'm hoping for decent play until I build a new PC this spring.
Yup, should have no problems. Cryptic might not want to promise anything with older cards, but I personally know that card will do just fine. In fact, you can even go as low as a 7600 GT (I tested it and it was fine for a 1280x1024 resolution at moderate settings). But a 7800 is fine, as it's even faster.