I've been on record several times here saying that I doubt we'll be getting new consoles this year even though they will be revealed at E3, but at this point, with all of the talk about this meeting and speculation by various people in the industry, Sony would lose a lot of points if they didn't reveal the PS4. I think all of the signs point at a reveal and this meeting has gotten a lot of hype because of it so they would foolish if they did something not related to next-gen.
As for the Vita patent, I read something a while ago saying that Sony actually filed several patents over the past few years for new designs for things like Playstation Move and the Dual Shock that ultimately amounted to nothing, so I wouldn't be surprised of nothing came from this. Although I think if they do bring up the Vita in the meeting, it will most likely be to talk about connectivity to the PS4.