Ribbon: go for it. Soon MS will also stop supporting XP, as Vista becomes legacy and XP becomes... really old.
Quicklaunch vs new taskbar: Installers cannot pin stuff for you, only the user can. No clutter yay!
Also I became so used to all the UI perks (hovering to preview stuff like progress bars, putting windows side to side, etc) that I unconciously do it in my Vista box. And then I remember that Vista sucks.