[jdh]

Unfortunately, I don't think this is even realistically possible. Apple doesn't allow third-party apps to stick stuff into the Notification Centre Today screen (yet, anyway -- but I wouldn't hold my breath either).

The only workaround I could see would be republishing OF tasks back out to the Reminders app, but that would get messy as there'd need to be a two-way sync between Reminders lists, and of course tapping on one would open Reminders rather than OmniFocus.