[mrubenson]

I know not all OmniFocus users subscribe to the full GTD system, so this comment might not be helpful in your case.

Anyhow, as I understand it, the separation between calendar and lists is intentional in GTD. Not everything in your calendar is actually a project or a next action – some things are simply just reminders of where you need to be at a specific time, but not anything that requires any action.

At least in my case, the calendar/OmniFocus integration is more than sufficiently well handled by weekly and monthly reviews. Do you do weekly reviews, and do you include iCal in those reviews?