I don't actually know where you're going with this...
We don't know much about Windows 7 yet do we?
Vista also looked a hell like XP on Milestone 1, but look what it became!
So Windows 7 will be a lot more different than the first picture we saw.
(I love wasting my time with Solitaire

)
remember how vista was going to blow away everone with all its new features> WinFS was going to be its biggest new feature, and then MS was late in getting it to market and they cut WinFS and other new features in Vista. I wonder now that MS is leaking out info and features like a touch screen support if some features of Windows 7 will get cut. I seem to remember a year or so ago MS said Windows 7 was going to have a new kernal. Now its been cut to an updated kernal of Windows Server 2008, which is an updated kernal of Vista

So what will MS cut just to get Windows 7 to market? Will MS just take vista service pack 2 and call it Windows 7 to get it out on time. ITs seems to me that is what they are going to do.
Microsoft cut the Vista features like WinFS and others because 4 years of development got wasted after they realised the XP and 2k3 codebase was completely useless for SLI devices, 64bit processors, memory management, privilege process security, exNTFS operations, LDDM drivers and hundreds of other factors all forcing them to rewire the entire Windows Basecode for the features they wanted to originally include with Vista.
Now they have re-written the codebase we might finally see the features that where ment to be included, they just need the time to re-write them for all the new Windows-Core changes that released with Vista, Its also so everyone can catchup with these new Vista Core changes before they release a heap of other new Core changes with Windows 7.