Maybe in terms of pixels, teraflops, gigahertz, RAM, memory, [insert more technical jargon], etc. But it doesn't look like it at all, at least not with my eyes. Most of the games shown looked like super-polished PS3 games, for the videos that actually showed gameplay. I guess that's one effect when graphics become so good that further advancements can't be noticed by the human eye. I believe the PS1 --> PS2 and PS2 --> PS3 were much more impressive.
Of course this is based on what was shown so far. I'll need to play it on an HDTV for my final judgement. And I will also have to wait for later games. Though I doubt I would have the ability to truly appreciate the entirety of the advancement.