Does anyone have a link showing that MGS4 only runs at 30 frames per second? When I google it, all I seem to get is 30-60 >_>;; at 720p gameplay 1080p cutscene. I might be off on that though.
Someone mentioned games like Halo 3 showcasing lighting, but if you had to render your game in 640p @ 30 frames per second... and it being the flagship title... is that really bragworthy? ;-;
For as much content is on the MGS4 disc, regardless of how much is replicated or wasted, it would be quite the feat to match the quality imo. I think it could be ported, but it definitely wouldn't be as nice in my opinion. Playing to one consoles strengths always makes for a better technical experience, and I think in terms of sheer technical scale, the PS3 wins hands down, the space, access to a hard drive, CPU power and faster ram make it a more technically sound machine.
In regards to textures, I could have sworn I'd read an interview with Kojima a long time ago about how he skimps on textures for things he doesn't care about you seeing, that and the fact that he loves to switch camera focus all the time... >_>;; Some of the textures in MGS4 are absolutely insane, some not so much, I'm not sure if I'd put that in the technically absent, or purposefully so.