They did it with Vista, and all their feedback was telling them that it wasn't ready but they pushed ahead anyway. 7 looks better than Vista and is getting some praise, but that's only compared to the clusterfuck that was the Vista launch which is still fresh in everyone's memory.
Frankly, there's no features that Windows 7 has that makes me want to buy it. I mean, if it had WinFS or any of the other 1,000 features they cut from Vista to ship, then maybe. But all they've done is make 7 less annoying than Vista. Sure, there's plenty of new eye candy, but if I wanted eye candy on my OS badly enough to drop that kind of cash then I'd switch over to Ubuntu full-time and go with Compiz Fusion (WAY more eye candy than 7, and most of the stuff 7 has was ripped off from Compiz).
I'm running 7 right now on one of my computers mainly because professionally, I need to keep on top of advancements like this. One the evaluation keys expire, I'm not gonna be paying to keep it though. If I'm given one for free through one of the MSDN things I'll take it, but I'm not gonna spend the cash they're asking for.