I loaded the new update for Mac Office 2011, update 14.5.0, and it crashed Outlook (no main window). I reloaded from TimeMachine and went back to the previous version. I don't know if this problem is universal, but it certainly seems common. If you have not already tried this update, I would suggest that you wait until Microsoft sorts this out. It is a real nuisance if the bug disables Outlook on your machine!