Since this app is inherently modal (you can only enter text when you're in an input field), it seems like a huge missed opportunity that it doesn't have VIM-style modal keybindings. Especially because it advertises it self as being for the text-editor set.
I will say that their no-signup approach to getting you into the app is pretty great.
I really like the fast start, but I would MUCH prefer them to allow me to give them some login info (maybe even just Google login or something) so that I wouldn't have to save a funky URL someplace. In addition to that, the option to have multiple trees (hit the holly button) is useless since only the browser that's seen all of your trees can access all of them (without the funky URL). It would almost be a feature if you could also forget trees that you've seen (keep a work tree and a home tree, perhaps, but no work at home). I think it badly needs the option of having a login or at least an unsecure custom URL option.
Because of no-signup, there is a great opportunity here for creating to-do lists for small collaborative projects. But Google-wave style simultaneous editing is not there (yet?).
Is that really lost if there's a login that keeps track of the individual list urls? I don't think they have to become private just because they're tracked.
For the record, I meant key combos that don't use modifiers unnecessarily, similar to GMails, where for example, just pressing “u” goes to your inbox. Modifier keys aren't necessary with modal interfaces.
Of course, at that point, basing your modifier keys on VIM just makes sense :).
I will say that their no-signup approach to getting you into the app is pretty great.