First of all, IE8 was a pretty fine browser, aside from the performance issues. It introduced no more bugs than new versions of other major browsers introduce (and yet I don't hear anyone complaining about those).
Granted, IE has a sordid history, but ever since microsoft restarted development on it, they've been noticeably improving the experience developing for it with every browser release, and IE9 seems to be set to do exactly that. So I definitely won't be complaining about IE9.
Well, ok, if they don't implement canvas or SVG, then I'll complain, but other than that ...
Yes, but unlike the rolling progression of other browser upgrades where FF users will upgrade, we will STILL have people running IE6. Maybe even 5 years from now! That's what galls me. The mindless, unbending sheep-like following that McSoft has now among corporate drone types. And the general drag this puts on development, and costs.