I wouldnt be an "intel fanboy", but I am a realist.
x86 / x64 is the only way.
The OS is going to have to be rewritten at some stage.
Might as well start now...
I'm guessing there is a 3rd way, which is what MorphOS finally did in supporting 2nd hand PPC Macs. A little late IMO, but better now than never. This is not a solution for world domination, but give retro hobbyist something nice to play with at a dirt cheap price. Hyperion taking this route with OS4 would have made more sense to me.
If either the MorphOS team or Hyperion really want to take a run at mainstream, I don't see any other option than x86.