I just wanted to report that many VF5 owners are reporting that the game does "upscale" from 720 to 1080 - it appears that pseudo "fix" (950x1080, or whatever it was) using the "hardware scaler" (a.k.a. RSX) is starting to be implemented.
From what I'ver read, it upscales to 1080 lines interlaced or progressive when you have the 720p option un-checked. I have no idea what the picture quality is like at 1080, as I don't have the game. I'll probably rent it and report back here.
Now hopefully insomniac releases a patch that fixes Resistance for those stuck in 480p...
(Sonic may have this fix too, but since the game sucks so much nobody has bought it to find out)