I wonder if they'll continue the pattern they've set so far-
Win95 => Win98SE : Win2000 => WinXP : WinVista => Win7
The OS changes on a more fundamental level every other release. (At least, this is how I see it)
So does that imply Win8 is likely going to be another 'rewrite' (not that they necessarily start from scratch)?
P.S. Yes, I am ignoring WinME.