[Brian]

OmniFocus syncs with iCal's "To-Do" database, but that's separate from the database that contains the events on your calendars...

Can you explain the workflow you're going for in a little more detail? If you just need reminders of these events - as opposed to having them be some set of tasks you need to accomplish - I think just leaving them in iCal is probably the best way to go.

The thinking here is that "hard landscape" items like meetings you need to attend go on the calendar; OmniFocus holds a list of actions you pull from to fill your productive times between those hard landscape items...

I may not be fully understanding your workflow though; if that's the case, just give us a bit more detail and we can try to help!