[tofumatt]

Apple will not prevent ad-hoc app distribution on the Mac; doing so would prevent Adobe from releasing Creative Suite on the Mac because of their non-App Store-compatible licensing.

Won't happen. Or if it does, easy: time to leave the Mac.

[lukeschlather]

For most people a $600+ dollar purchase with highly depreciating value is not something you can just walk away from.

[aristidb]

Given that this will certainly not happen in the next 2+ years, I think you would have gotten some value from the device by that time.