I'm having hard time with choosing the final resolution for my project as well. After doing some research I struggle between 1280x800 and 1280x768.
I heard that 1280x800 is very popular. However, my new laptop can go 1366x768 tops, it can't use "anythingx800". Similarly, all panoramic monitors in my office (of different brands) can't go "higher" than 768 as well, so I'm not so sure about this 800.
On the other hand, 1280x768, although appearently not very popular, for pre-rendered WME games seems to be just fine. All laptops I've recently seen and newer panoramic screens have this resolution available. My regular screen (not a panoramic one and not that new) also supports it. And if someone use higher resolution, WME will just add black stripes, right?
So what about 1280x768? Would there be any actual problems with it?