Freescale are pretty big. They don't make mockups just for fun.
I'm starting to save from now.
Oh, and if it ran on ARM, there's no reason it couldn't run applications designed for the iPhone. The iPhone basically runs a stripped down version of OSX with a different UI layer (i.e. UIKit and it's own UI layer instead of AppKit and Aqua). If Apple ported AppKit, Aqua and the rest of the missing frameworks to OSX on ARM, they should be binary compatible and run a full version of OSX, although it likely wouldn't be compatible with current applications (without Rosetta, but ARM processors are typically not powerful enough to run applications like this very well).
iPhone OSX is a subset of OSX with a few extra frameworks. Port the outstanding frameworks to ARM so that it becomes a superset of OSX, and you get an OS that looks and feels just like OSX, can run the same applications (with a recompile or Rosetta) and can run iPhone applications. Similarly, if you ported the iPhone-specific portions of OSX to standard OSX, you'd get an OS that supports what OSX does today, and iPhone applications with a recompile for x86.
I think the latter is the smarter choice. That would force the tablet to be x86-based, but it'd pave the way for a future iPhone running some sort of Intel Atom processor, so that Apple would only have to maintain one version of OSX.