aha, i recall such a thread when vista was out, a bunch of screenshots made by somebody, posted here at MR.My big problem is that within Vista itself you'll have applications with wildly differing layouts and button schemes. I had a picture at one point that pointed out all the different schemes with the bundled applications alone. It seemed like they didn't even try to stick with one predefined usability outline.
Menus or nonexistent menus. Help buttons or accessing help from the menu.
To be honest, I dont believe that was fair nor was that a big deal, I used many vista machines, so do the friends around me, nobody complain that much about those.
The fundamental question is if that really slow down and/or causes problems for end users, I dont think I saw any such report saying users are unhappy with it. Microsoft conducts user experience research, not like they do things for no reasons.