Excellent app! I've been playing around with it for an hour now and can really see myself using it.

Inline editing is the one feature i miss the most. Also the tree list is a bit hidden. If they were visible you could switch faster betweem them and setup the app as a lightweight project management tool or issue tracker. Just add your users, milestones etc as own trees and copy/paste between them. Also a syntax like: (someissuenumber) ... which renders issue number in front of the line would make it kick-ass.

Great job!