Just noticed the Outline tab this morning and I'm really excited about it...!
I agree with shelby.p (above)... Having an outline linked to a task would go far to address my need for finer granularity with Tasks (i.e. define the "end result" at the Task level and work within the outline to make it happen).
However, I also forsee how this model would have limitations (example: a line item in an outline suddenly needs a Due Date, additional Notes and an Alarm attached to it...)
Maybe a good MVP would be to allow an line item to be converted into a task that - at first - inherits the parent Task's Folder, Goal, Context, etc... If the outline is NOT attached to a task, then those properties would be blank/default.
This feature, I think, would be a very quick thing to do (after you create the first feature of connecting an outline to a task...)
Lastly... A big +1 for getting Outline into iPhone app ASAP..
Good Luck and you just kept me for another year...!!!