I'm sorry but I had to laugh, the last thing MS has is a great design team, it's a fucking mess. It's truly a bunch of ideas thrown together without much care for consistency. Incorrect padding, ui menu overlappings, weird use of colors, icons in many different styles, etc..
Windows Phone shows that they do have a great design team. I'm guessing it's just slightly harder to create a completely consistent experience in an OS that has to maintain 20+ years of compatibility.