Currently Being ModeratedNov 28, 2011 1:48 PM (in response to kernanmk)
No, in Lion you can define one default calendar (can be chosen in Preferences>General>Default Calendar). All new events will at first belong to this calendar. You can then i.e. by ctrl-clicking any event call up a dialogue in which a different calendar can be chosen for the respective event.
Currently Being ModeratedNov 29, 2011 12:59 PM (in response to kernanmk)
Update: In order to have iCal react similar to what you might be used to from previous versions of OSX do this: Open Preferences>General in iCal again. In the section where one can choose the default calender scroll down to the very last entry, which reads "Last selected calendar". Once that setting is taken and back in the main window of iCal, you can highlight the preferred calender in the calender list and then create a new event as usual. Voila, it will belong to the selected calendar. All credits please to the folks who participated in this discussion: iCal Lion is infuriating. How can I add a new event in a chosen calendar without having to create it in my default then edit it?