I really don't see a 2012 reveal for the PS3 at all likely. PSV will of only been out for 4 months in the western world by the time E3 2012 rolls round, announcing a new console right after launching a different console ? that would certainly be interesting.
Assuming the next xbox comes out in 2013, the ps4 will have to come out in 2013 or 2014. The ps3 suffered a great deal from being a year behind. Sony isn't going to double the lag. And, as is the speculation, I believe the xbox will almost definitely have bluray.
Thats a solid theory, but the problem wasn't that the PS3 was a year late, it was the joint fact that it was also only just as good as the 360, the differences wern't significant. If the PS4 is 2 or 3 years late to the next xbox, it will also be significantly better, so they won't really be competitors. Just like the Wii isn't really competing with the PS3 and 360.