Ars Technica: Inside the IBM PowerPC 970
Very in-depth and filled with complicated technical details. Worth the effort you put into it, giving a good description of the technical differences between the 970, existing G4 and P4.
I'm really looking forward to the new processor, because I think it will put Apple much further ahead in the technology race than they are now. Another year to polish OS X more and then a new architecture to dump it on so it'll scream? I'll definitely be saving for a mac...