Unlike ME, which was a nightmare from beta to thankfully short end-of-life, the vast majority of Vista's bugs and problems were fixed with SP1.
HD is right, however, that most businesses are avoiding Vista. That's not because it's a bad OS any more, it's because they don't gain by switching. If you have to put forward a business case for changing Operating System on several thousand PCs, you have to have a very good reason to do so and the changes that Vista has brought - some good, some dire - are nowhere near enough to tempt companies away from their stable, understood, XP infrastructures.
Microsoft did shoot themselves in the foot, by pulling XP early to try and boost Vista sales. That was stupid. Windows 7, so far, looks like what Vista should have been at release: Still bloated, still full of unnecessary rubbish and restrictions, but it runs a lot better on the same hardware than Vista does, according to most accounts I've read so far. Will the release version? Dunno. The same as Vista, I won't be touching Windows 7 until after SP1 is released to fix the most glaring problems.