Contrary to what many, many companies and developers want us to believe, widgets have nothing to do with those annoying little "programs" running on separate desktop layers or whatever. Traditionally, widgets refers to UI components - buttons, checkboxes, text fields, whatever. In this particular case, I want to talk about the rather curious placement of the titlebar widgets.
Of course, there are two places to put these. Windows puts them in the top right corner of the window, and this setting has been adopted by KDE and GNOME. The Mac, however, has traditionally put them in the top left corner of the window; the argument is that people read from left to right (in the west, at least), and as such, it makes more sense to put them on the left.
Cue the new Ubuntu Metacity theme. Since Ubuntu uses GNOME, the titlebar widgets have always been placed in the top right corner in Ubuntu. However, the new theme places them on the left. This means a switch to the Mac way of doing things - sort of. The curious thing, namely, is that the close window titlebar widget is not the left-most one - it is the right-most one!
I find this remarkably curious, as I've never seen such placement before. I'm extremely curious about the justification for this placement scheme, since I can't come up with a logical reason myself.
Now, have fun checking out the new material.