There were 2 PPC 4000 Amigas with amiga 4.0 on it.
I played with one of these...
It was pretty responsive...the mouse pointer was a little bit wobbly, maybe it was the mouse.
I ran through the menus, checked some programs (opus didn't work, Ibrowse...). There was nothing 68k based to try the emulator. Well I didn't see it.
But it looked good, as a say it was responsive and fast, but the amigaone version should be superior to the PPc version. Well it's nice to see they are working on something... And as I said before the release date should be September (this year :-D ).