IE7

I'm on the beta test program for IE7, and I must say I'm underwhelmed in general.

Yes it has tabs
Yes (impressively) it does alpha transparency right, but not the gamma correction of alpha-blended colors (not in the same way that ie6 gets it wrong though)
The interface is moved round so it looks weird, url bar along top (below title bar), refresh button after the url input field, file menu last in the toolbars.
It fails the acid2 test in the same (drastic) way that ie6 does.