>Lets see Powerbook and G5 support first.

I'd definitely second Zylesea's opinion. These solutions would be faster and still be compatible with our current base of software. They are also fairly inexpensive (although obviously more than $25).

Frankly 700-800 Mhz isn't that impressive. And we still don't have SMP support, so multiple cores aren't useful.
As ARM moves toward 2Ghz and higher, it then becomes a more attractive solution.