[Hoff]

Hmm... In strict GTD, this situation sounds like you have 2 tasks: 1) Joe paints the house (in @Waiting), 2) Remind Joe to paint the house (in whatever context you would apply to the next time you want to contact him). One task for Joe, one task for you.

That's all in Focus right now.

It seems that some of this could be automated. Perhaps Focus could recognize @Waiting (or whatever) as delegated tasks and automatically prompt for a reminder or follow-up task? Perhaps you could attach multiple contexts to a task?

I can see this stuff being helpful, but also possibly as unnecessary additions to the UI. Above all, I think this thing needs to be simple, simple, simple.