Ditto on the menu bar. I like it. Not to sound reductionist, but it reminds me of Ubuntu (second best OS out there, imo).
I do miss the rounded edges on the menu-bar though. The rounded edges are one of the key little visual cues that remind me I'm on a mac. Hope they bring those back.
I like the new brighter colored traffic lights, but they don't seem to be "embedded" in the window frame. Rather, they seem to be sort of pasted-atop. Hope those get polishing.
I don't hate the little blue lights that indicate a running application nearly as much as others. I welcome the change, although the triangles do a better job of clearly indicating what's open and what's not.
Have fun with it.