Vista has gotten a bad rap one that isn't as deserved for what it is. It does a lot of things easier than XP ever did and it does look a lot better. It is a hardware hog though and it does have some compatability issues with software and drivers that have been mostly cleared up unless you are using the 64 bit version.
That said this is not the first time this happened. Windows releases 98 and then 98 SE and then ME(which was horrible) and than XP(which was based off the much more stable NT line(3.1 NT 4 and 2000).
That said there sin't even an alpha leak yet for 7(Vista(Longhorn) alphas were out in 2002). XP(Whistler) Alphas were out in 99.
My guess if it is released that early. MS was originally working on two lines for Windows 6 Longhorn and Blackcomb. No one ever got a Blackcomb alpha as far as I know and it was scrubbed. MS wanted to release a new file system WinFS but it was not part of the final release of Vista(Apple wanted to release ZFS and it was not released with leopard either). Though you can find evidence for both filesystams in either leopard(spotlight zfs) and Vista (search for winFS) although being system files it may be a little more difficult to find.
So I guess they are goign to implementing WinFS in a whole New OS which will supposedly allow for some of the snazzier ideas they were working on who knows.
My prediction Windows seven in 2010 some screenshots were leaked from an early version a few months ago. While they look a lot like vista the early versions of whistler looked like 2000 and the early versions of longhorn looked like XP with gadgets(worst idea ever)







