God, every time I see a screenshot of Firefox 4 I get hit with a nostalgia blast. I was in highschool and I remember getting hyped up about the UI overhaul from teasers Mozilla was putting out. Felt like Christmas when I hooked up to the dorm wifi at the table in the lounge and got the update notification.
https://static.digit.in/fckeditor/uploads/ff4-newui.png
But they probably figured that the more like Chrome they are, the better...