It would be nice to have the possibility to add annotations to contexts (people) and projects. Annotations of tasks are possible now, but simple annotations (that may be sorted on date) aren't. (Or did I miss them).

OmniFocus would not only be a tool plan your tasks, but also to create a log of things you've done, things you've told someone, things you've agreed, etc.

In Prince II, a project log plays an important role and OmniFocus couldn't help projectmanagers with that.