How many of you understand the real difference between 30 fps and 60 fps?

60 fps is 16.67ms of processing time per frame.
30 fps is 33.33ms of processing time per frame.

Which one do you think will look higher quality, given the same engine technology? The one with 2x the framerate of a TV, or the one that uses 2x the horsepower to render an individual frame, and the same framerate as TV?

30fps means the game is doing a lot of cool stuff, or the engine was written poorly.  Given SCE's studios general quality level, I would say its the former, and not the latter.  Most people who think they can see the difference between "30 fps" and "60 fps" are actually noting the difference between "20 fps" and "30 fps" -- because, yes, accurately telling the difference between 30 and 60 is usually something only trained professionals can do without an on-screen counter, no matter how awesome you think your eyes are, relative to the rest of the human race.

A heck of a lot of games run at 20 fps, and people don't whine about it, although 30 fps is a clearly notable boost over 20.  60 fps is a minor benefit usually only afforded to games that are simplistic, in terms of rendering, like racers and space games, or PSN/XBLA grade titles.

Off the top of my head, the only games I can even think of, that run at 60 fps this gen, are some racers and little downloadable titles, which is exactly what I would suspect.  Anything else that runs at 60 is going to be called "last gen" by the reviewers, for its low-grade graphics.