You'll still be able to play it at 800x600, it'll just either stretch to fit so everything's wide, or it'll stretch so you have black bars at either end of the screen (but keep the aspect ratio).
Hope the screen's OK for those of you who have bought it, but with the response time and viewing angle specs it looks very much like a TN panel, which will give you rubbish viewing angles, especially when viewing from low down (i.e. from a bed).
Also, I presume the contrast ratio is a misprint? Most monitors are about a tenth of that!