No, what I have heard from a Mac developer friend is that Apple's Xcode tool chain is likely able cross-compline x86-64 applications to ARM with relative ease.

No, what I have heard from a Mac developer friend is that Apple's Xcode tool chain is likely able cross-compline x86-64 applications to ARM with relative ease. By forcing developers to move to 64bit last year, much of the work will already be done for the ARM transition. (Of course, there are always difficult cases that will take lots of work)