Graphics Showdown - Uncharted 2 vs MGS4 vs Killzone 2

[Reasonable]

Is this based on opinions or actual technical capabilities? Just curious.

Personally, putting aside any preference, I'd say the situation is:

Uncharted 2 then Killzone 2 after a small gap and then another small gap to MGS4 - looking at animation, character models, resolution, fps, on-screen activity, various stuff like particle effects, etc. and flexibility of each engine - different environments, foliage handling vs buildings, etc.

Personally I prefer Uncharted 2 for overall looks with Killzone 2 and MGS4 a draw for general looks and art direction - well, maybe a whisker of preference to KZ2 for the Helghast designs.