Nobody's building desktop/laptop motherboards with them at the moment. That's unlikely to change in the immediate future, but the industry can take surprising turns some times.
It will never happen. Never EVER *EVER*
**EVER!**If the industry will want something else than x86, it will be ARM. In fact, that process has already begun, and you will start seeing results of this during the current or upcoming few years...
Anyway, this from a guy with a MOS avatar?
Most people today (including the MorphOS developers) understands the situation with PPC. Some MorphOS developer said on morphzone: "If we had know back then, what we know today about PPC, we would have choosen differently". That's why the plan is:
1) Short term: MorphOS 3.0 for PPC
2) Mid term: MorphOS 3.1, 3.2, 3.3, etc, ..., ..., for PPC
3) Long term: Re-evaluation about the CPU/HW situation, which may include a migration (to x86, ARM or both?)
We are using PPC only because this is where MorphOS currently is, not because PPC is the best, or even good enough (anything that can't play 1080p movies in 2012 isn't good enough).