Software compatibility? For AROS, sure, but not for AmigaOS! Other operating systems - Linux is on ARM and x86, Android is ARM and soon x86.
Samsung will have their 2.0GHz ARM Cortex A15 dual-core out early next year - that will outperform even the fastest Atom (event the 2.13GHz ones). The ARM ecosystem is simply far more interesting at the moment.
Windows 8 will also have a release on ARM.
But both are to pedestrian compared to £400 i7 PC right now let alone in the future years.
IMO just convert OS4 to x86-64bit and be done with it.