I voted ARM myself. There just aren't enough/any apps right now that I need to put AROS/Amiga on a x86 system, I'll need linux for apache, owncloud, mplabx, libreoffice, viking, etc
The Pi's and other ARM's, while they can run Linux they are not the speediest in the world, so why not make Amiga a lightweight OS for a lightweight board, there could be a market there.
