Shuttleworth: Unity shell will be default desktop in Ubuntu 11.04 (ars technica)

My experience is that the global menu on Ubuntu is more usable than the OS X one (if you ignore a couple of bugs). The reason being the rather strange focus policy on the Mac, and the fact that applications stay alive (and with their menus active) after you close their last window - together these lead to the menu at the top often belonging to a different application than I (admittedly a Linux user, not a Mac one) tend to expect.