well Yoshida is SCEWWS (SCE software) boss he should be there
I don't remember Howard Stranger being in PS3 reveal back in 2005 or any E3, this is why I doubt that Kaz will be there, it just sound like Sony always want SCE people only to take care of this PlayStation business.
then again looking at the situation the entire Sony group depend on PS4,so Kaz might be there but I still don't think he'll do all the talk.
In all seriousness, I really do hope that Ridge Racer is there or at least ready for the console launch. Hopefully the team has had long enough to develop it. I think that they only had a couple of months to put together RR on the Vita, which is why it's so lacking in content.