They've always been fragmented.. ever since the Symbian S60 days trough the MeeGo days, etc.
Lets hope that Microsoft can clean the house and streamline all of that mess.
End of March.
Its all about being able to turn "metro" on/off.
For people on desktops who don't need it, have it off by default and replace it with some sort of a start menu.
For every one else...
Update 1 changes things for "traditional" machines, metro for touch based devices should remain the same as it is in 8 and 8.1 ... I don't see what the big deal is
They need to get rid of those and base the whole UX on the swipe gestures seen in Windows 8 ..