I'm curious if anyone has tried this.
Seeing as there is absolutely nothing added to Media Center in 8/8.1, only compatibility removed, the only reason I can think of why it is recompiled for each Windows version is because it is primarily a .NET app, and Windows 8 doesn't include .NET framework 2.0 and 3.5 by default.
I am curious, assuming .NET 2.0 & 3.5 are installed first, if the C:\Windows\ehome directory is transplanted from a Windows 7 box to a Windows 8 box and all the .NET assemblies within it re-registered, will it run? Does it yield compatibility with add-ins and extenders? Would DRM protected content fail on such a transplant?