I'm slightly serious about this, but what if Apple decided to finally release a PowerBook G5. They're already got the new MacBook Pro to deal with the serious customers who want what the PowerBook G5 would have offered, but just to say "Yeah, we could do it if we wanted, but why would you want us to," they could come out with one. Make it about 3" thick to accommodate the water-cooling mechanism and the rest of the massive components, and just remind people that if they really wanted a PowerBook G5 they'd better be willing to sacrifice for it.
Oh, and it'll cost $4999.
jW