The whole idea of the PPC's just give me the shivers. I know I'm going to get flack for saying this, but I never really got all excited about them. Call me a pratical x86 whore if you will.
Most of the PPC hardware applications (if not all of them) in on way or another were outrageously expensive for my taste. In the case of the Macintoshes, they were just overpriced period. I've known people that would literally have an orgasm when a new Mac came out, but not I.
As far as using ATI, is that really a good idea? I mean ATI as some good things, but as a whole a lot of there chipsets don't perform as well as the Nvidia counterparts. The lack of real unified drivers, okay I'm not going to get into this.
This talk of OS4 and hardware sounds like a bunch of 16 year olds on a chat network in an automotive room. Talking about their V8 powered, turbocharged, balanced engine timing, polished aggressive camshaft, blah blah blah. Unless you have a real product, it's all talk.