I heard someone talk about it recently (and I'm pretty sure I remember a PS4 logo myself). It may not have been in the version of the trailer revealed at the conference but only in the version of the trailer uploaded to YouTube or some such thing. Or maybe, if my memory is very off, it may have been on the game's website rather than in the game's trailer but yeah, I'm pretty sure that there was a PS4 logo somewhere. Of course, though memory is a funny thing so I may be completely wrong even though I'm pretty sure.