Up until Lion, I could double-click inside a particular date (in Month view) and it would automatically create a new event whose time that day defaulted to one hour. I could then change the starting time, and the ending time would automatically adjust to be one hour later. This was often good enough, and made adding an event very straightforward.
In Lion, the same action produces an all day event, which I then have to bring up in the Inspector, switch off All Day, and edit both the starting and ending times. It's a good deal more work. I don't see a Preference for this. Does anyone know how to restore the pre-Lion behavior?