We know that Apple doesn't release half-assed products, so we know that when they're ready to release the Mac Pro replacement, it'll most likely be impressive.
I wonder if we'll see expandable memory, which might be done with some CPU local memory which could act as a large cache, and / or which might act like main memory with expandable DIMMs used in a way analogous to swap. It wouldn't surprise me if Apple were to make a new model for memory.
Also, I can't imagine that adding PCIe lanes to their CPUs would be a big task for Apple. It's not like they forgot that a Mac Pro replacement would need them and are now somehow rushing to figure out how to add them.
If Apple decides to add external GPU options, it'll be interesting to see how they'll schedule work between their own GPU cores and external GPU cores - will it be based on data locality? Based on the relative strength of each kind?
And while I'll never buy a Mac Pro, I'm excited to see what an ARM-based Mac Pro would be.
A little nitpick: when a chip's speed is set by the maker, it's not overclocking ;)
