I would love to see a Rasperry Pi type device with a PPC chip on it, a 603e equivalent for example, or even better, a 7400 series "G4" chip.
Costs more than the Raspberry Pi though.
Admittedly it was a smidgeon more expensive than the Raspberry Pi.
They're making a kajillion PPC based processors for the Xbox 360, PS3, and Wii, so it's not like they don't have designs for current manufacturing processes. The chip in the 360 can't cost more than $50 today, and if stripped down (2 cores vs. 3), clocked less aggressively (1GHz vs. 3.2GHz) could probably be cut to $25 or less.