What we heard so far is basically this:
ND- U3 team doing nothing for a year- probably PS4 development started
SP- they had a new IP that they were working on one year ago (when I2 shipped) but no idea what system it's on. Anyway they have 1 year and half of silence
GG- They are making another Killzone title, we're not sure for which console, and one new IP, presumably an RPG. They've been silent for 1 year and 10 months
Evolution- silent for a year and a half. Motostrom for Vita was made only by a very small team. Some say they took over Wipeout and integrated some people from Liverpool in there.
Sony London- busy with Wonderbook and one can imagine they are working on taking Home out of beta for PS4
Sony Cambridge- working on Killzone Mercenary as part of GG
Media Molecule- working on Tearaway, have a second team doing a new project. The studio has been quiet for a year and 10 months.
Sony San Diego- MLB The Show every year and they are apparently working on Warrior's Lair for Vita
Sony Bend- Working on Vita
Sony Santa Monica- Stig has a team working on a new IP, Pappy's team is working on GoW:A, incubator for many small studios, the team behind the Unfinished Swan are to release 2 more Sony exclusive games still.
Ready at Dawn- working on a new IP for next-generation, rumored to be a Sony exclusive
Studio Japan- They have Rain and Pupeteer coming out. Rumor has it that Gravity Rush sequel for the Vita is in works. They are helping with Soul Sacrifice. They are making TLG (lol).
Polyphony Digital- technically part of Studio Japan but they have been quite since the release of GT5, though they did improve the game through patches and DLC. They are working on GT6, safe bet is that it's a ps4 title.
Quantic Dream- working on Beyond, still have a contract to do one more Sony exclusive game.
United Front Games and Sony seem to also have a good relationship, but their games on ps3 have tanked recently so I'd say they might stick with SE and work on the Sleeping Dogs.
So definetely PS4 development is well underway in most of these studios and we'll see some high quality titles for launch, no doubt. The one worrying thing is that only 4 studios seem to doing any work for the Vita.