In latest message Quaz51
claims the game uses 640p with no "AA", however I'm not sure if it's true. It could be the size of an internal framebuffer since the console outputs 720p resolution. Besides I didn't see any difference between the both versions on any screenshoot I saw - the all look the same except for color parameters (like gamma, saturation, etc).
Other strange thing is the support for 1080i/1080p. The game box has a sign that means the game supports for PAL, HD 720p, 1080i, 1080p while the game runs in 720p for me (while all other modes are enabled in XMB). I found no option to run the game in 1080i/p modes and the game choose 720p by default (I did not try to turn off 720p while 1080i is enabled). Furthermore Test PS3 shows "Resolution = 0x2E, 1080/720/576/576(16:9)."
string however it can't run the due 2.15 version of firmware (till the leakage of newer debug firmware