There are no plans to drop PPC anytime soon. There is no need to.
There is next to nothing in PPC asm. Current applications and tools, if they play by the rules, just need a recompile for a new target platform. However, due to the AmigaOS API and there are a few tweaks needed to "fix" those applications. Afterwards they can be compiled for PPC and NG.
I could do lowlevel. :) Its just no fun for me and I prefer doing something with some visible result for a change. For MorphOS the lowest level of coding I did so far is the netprinter.device AFAIR.
All team members are listed in MorphOS about. There aren´t any more.
The target platform will be choosen by the MorphOS Team and not by a few people with wishful thinking. There is plenty of work required *before* choosing a final target platform, so no need to stockpile potential target systems. The current hardware situation isn´t bad at all, which is mostly because of supporting apple hardware, which also was well planned before.
I know people claimed the MorphOS Team wasted time on the SAM460. Sales wise you are right. And it was predicted by the Team. But it had some sideeffects everyone using MorphOS right now benefits from. Huge parts of the boot process and the kernel needed to be rewritten/cleaned. Tons of bugs sitting there were found and fixed. Stuff optimised. Less memory used. So the other systems are now even more stable, have a little more free memory for applications and boot faster. Starting with the Efika and Ending with G5 Systems. It also (main reason for supporting the 460) allowed to support X5000 boards (getting it to boot) in hours instead weeks.
So in a summary it wasn´t a waste of time at all and everyone benefits from that.
Now imagine what happens when a target as different as what is next gets supported? Even there the PPC path can benefit alot.