[convergent]

Yes, of course, when I said "Win32" I was referring to the 16 million or so Windows desktop apps out there that the Windows 10 on ARM emulation layer is intended to support. The lack of support for these apps -- which I'm guessing developers won't be so quick to recompile for ARM, any quicker than they've been to make UWP versions -- is what killed Windows RT (among other things).

And, I would submit that even if Autodesk recompiled AutoCAD for ARM, it wouldn't perform as well on a Snapdragon 835 as it does a Core i7.

I totally agree with you on that. There have been many platform change attempts on different systems that failed miserably. The one that I thing was very painful but did succeed was when Mac moved from PPC to Intel. But they were pretty much all in on it so it had to work. I have my doubts on whether moving Windows to another processor platform will succeed, and I guess its tied to Microsoft's UWP strategy. They need that to work for their long term strategy... remains to be seen if it will be.

[Cruncher04]

Do you think that developers are going to want to recompile for ARM? I see that being a problem if they need to have different versions of their apps for a different processor... will become fragmented and inconsistent.

From developer perspective, the app is the source not the binary so it is very much the same version and there is no inconsistency.
My expectation is, that open source Win32 apps will become available for ARM very fast, so are .Net/CLI apps.

And, I would submit that even if Autodesk recompiled AutoCAD for ARM, it wouldn't perform as well on a Snapdragon 835 as it does a Core i7.

Sure, currently if you want to run professional high end apps you better invest in an i7 anyway. I mean a Snapdragon based tablet (and so are Atom and lower end Core models) is not the best choice for professional applications anyway. Thing is, the newly introduced Cortex A75 is 20% faster than Cortex A73 in Snapdragon 835 and next years ARM will again be 20% faster. So ARM is closing the gap fast to high end Intel Cores.
By introducing Windows on ARM Microsoft lays the foundation for an ARM based Windows ecosystem before it is too late for them.