I sat in the IE8 presentation at Microsoft tech-days ... oh boy
While showing the new features such as 'look, one tab locking up now doesn't bring down all your tabs' you guessed it, the entire browser completely locked up.
The 'malware protection' allowed the sample virus and malware sites to download quit happily and the questions from the audience included 'is there a Firefox plugin that supports the new smart tags?' (there was, and there was much rejoicing).
IE8 is a big improvement on IE7 but unfortunately, Microsoft have lost the plot and the momentum with browser development and the whole rendering engine switching is a complete and utter mess (they expect end-users to have to choose IE7 mode, IE8 compatibility mode or IE8 standards mode ... are they mad? Why don't people have to do that with other browsers?)
Worse still, they expect IE specific markup to support their mistakes.
One thing that made me laugh though was support for the new CSS3 box model which is a much more logical and is 'the coming standard'. It seemed awfully like the old IE box model which IMO was always the correct and sensible way of working compared to the 'dumb' standard that everyone insisted we use.