Currently Being ModeratedMay 1, 2012 9:15 PM (in response to Elege)
The calendar side bar is a drop down menu in Lion. To see the calendars you must click on the "Calendars" button in the top left corner of the iCal window. The list is designed to disappear when not in use.
The feature you are looking for does seem to be a part of the next version of OS X, Mountain Lion: http://www.macworld.com/article/1165436/mountain_lion_hands_on_with_contacts_and _calendar.html