Just a couple of things on Windows 8.1 (codename Blue) in relation to the musical screne:
The start button is back but the start menu is not, it simply opens the start screen.
MIDI is still not supported in the WinRT environment. The Windows 7 portion (desktop applications) of Windows 8 still works like before, of course.
As for MIDI in WinRT and if you want to see MIDI added, posts regarding this exists here, here or here. There is obviously a similar MIDI denial/confusion at Microsoft, as there was in the Apple iOS camp. Something new is obviously needed in the world of music and MIDI, but there seem to be no apparent and satisfying answer. So get involved if you know, need or otherwise feel strongly about MIDI, so that we can use new AND old MIDI equipment in the future.
It would be awesome if someone at Steinberg could whip together a Windows Runtime Component (and possibly a driver/firmware update) that talks with Midex8 and for Steinberg to again be the pioneer of MIDI. (THEN start porting something like Cubasis to WinRT.)