Actually Portable Executable
I think heterogeneous computing is actually coming this time.  Increasing binary size requirements wherever portability is required will be an intended sacrifice toward that aim (but for app store based distributions - the only place required to pay the binary size tax will be in the size of the bundle provided to the app store vendor).I think the importance of ISAs will fade away generally in favor of specifications that enable coordination of higher level memory model semantics "across" compute resources -- the cpu/compute core becomes the thing that allows you to share reads and transfer write ownership of memory as efficiently as possible between heterogeneous components that operate on the compute graph -- and many of these compute components may require various binary forms of task specific instruction encoding ...