Still If they shit focus to Vita completely and don't let their studio work now on PS4 projects (when it's clearly Microsoft preparing to their new system already) then PS4 will have even worse times than PS3..hell it might even kill the PlayStation brand altogether.
What Sony need to do ( to don't repeat the PSP lack of support mistake and don't ignore the fact that next gen of consoles is coming soon) is to have a Portable/handheld team within every one of their major studios.
Sony would never move focus completely on Vita nor move focus too much away from Vita either (that's why they have all these new partners they've put to work on Vita games in addition to quite a sizeable chunk of their own studios). They are probably in the process of phasing out PS3 development slowly but surely. If I had to guess (and if my prediction of a ~mid-2013 launch for PS4 turns out to be true), I'd say:
1) Evolution Studios & Naughty Dog have already moved/will move on to PS4 development since both released a game this year and Evolution Studios will perhaps better serve as working on a PS4 launch title instead of another Super Bombah Motorstorm for PS3 in early 2013 (better awe everybody with a PS4 launch title and get a sales boost from launch sales). PS4 will need first party launch/first year titles and if PS4 is launched by mid-2013, Evolution Studios could get a launch title done and Naughty Dog a holiday 2013 release.
2) Guerrilla Games, Quantic Dream, Media Molecule and SCEA Santa Monica might each still have PS3 games set for late 2012/early-mid 2013 releases so that their output on PS3 doesn't stop too early before PS4's arrival (and might even continue a while after its launch), but GG's second studio could be working on a PS4 game. GG's second studio could also be working on a Vita game (they did make KZ Liberation for PSP). If the second team is developing for Vita, in that case I'd say that the "KZ studio" isn't working on PS3 anymore, but maybe they've started to work on a PS4 launch title as soon as they shipped KZ3.
3) Polyphony Digital might not develop GT6 for PS3, instead it'll be a year 1 (year 2 after delays

) release for PS4
4) Zipper is working on their Vita launch title & PS4 game simultaneously
5) some kind of output from SCE Japan too ((either) through collaborations/publishing deals with devs like Level 5 & From Software and(/or) something in-house, Hot Shots Golf 7 or the like)
6) Sucker Punch's next game will either be one of the last first party games for PS3 or one of the first for PS4
7) in addition to their Vita launch games, some SCEE UK team's have been hard at work on PS4 games too