I don't like the feature explosion. There are a lot of new features in there that I'm probably not going to use. On the other hand, a basic download manager that can pause and resume is still not there.

Suggested sites: useless
Webslices: not going to use it
Compatibility mode: I guess we're stuck with it for the next 10 years because Microsoft screwed us in the past 5 years
Selection: every time I select something I get this weird green button that I don't need
RSS bookmarkbar (bookmars with a popmenu with all the rss items): I use it all the time with Firefox.

Will it gain marketshare back from Firefox? No.