"No legacy apps" is not the same as "no Desktop apps" though.
Nothing I've seen suggests that there won't be a regular Win32 with COM, IE, MSHTA, etc. on ARM along with an Explorer Desktop.
You may simply need to recompile C++ or .Net after some tweaking or "retargeting." Things like HTAs may even port with close to zero effort as long as they don't use any custom COM libraries. I'm surprised anyone ever expected any x86 code to run on ARM, even under some sort of WOW emulation. Microsoft has been pretty clear about that.
Whether it makes any sense to do much of this (desktop apps on ARM) is another matter, even if you can. The ARM-based devices are likely to be quite resource-constrained, which is the purpose in having them in the first place: cheap and portable.