You can have Omnifocus tasks within the appointments (events) area of iCal, but this requires that you are syncing OF with a WebDav account. If you are, then just subscribe to the DueSoon.ics on your WebDav account within iCal. Your tasks should then show up.
If you don't already use WebDav sync, get yourself a
www.mydisk.se account which is free - you get 2GBs of space and it works well.