I suspect I’m the very last person in Notational Velocity world to discover this, but NV now has some nice basic outliner/todo list functionality. Appending @done to a line will strike it through, bullets are automatically added (you can use dashes or asterisks) and you can shift items up or down the list hierarchy using Tab and Shift + Tab. A boon for Taskpaper users, I imagine.
If, like me, you’re two months behind on NV news, this January post details a bevy of new features, including the above, wiki-style inter-note linking with [[double square brackets]] and a horizontal layout.