Technically, The Last Guardian could have been in development since SotC released about 10 years ago, but it's quite unclear when (and if) development started on PS4... Media Molecule is supposed to be working on that new project since Little Big Planet 2 released 4 years ago (Tearaway was a small side project). Guerilla Games announced that they were working on a new IP in 2011, i.e 4 years ago. Bend Studios switched to PS4 at least 2 years ago if we believe the latest rumor. Quantic Dream's new project was in pre-production back when Beyond released, 18 month ago.
I believe Quantic Dream will communicate on the inevitable Beyond remaster before we see anything on their new project. And if indeed Bend has been working on a new IP for two years, we may have to wait a bit longer before we hear about that too (new IP takes time, switching from portable to home console isn't that easy, ...). And of course, The Last Guardian is a big unknown, they could be polishing the game as we speak just like they could decide on giving up this whole mess... In any case, I expect it to release right after its hypothetical re-reveal.
Mm and GG's games should be unveiled this year though, and I would also put a few bucks on Guerilla Cambridge's new project and Gravity Rush PS4.