It's interesting, but the vim editor has the same problems that most near-vim tools have: my muscle memory (trained with my vimrc) is all wrong. Escape is an awkward key, so I exit inset mode with jk and kj. $ and ^ are weird, so I jump around the line with L and H. My leader key, my plugins, etc are all sorely missing, and trip me up here way more than a purely non-vim interface.

What I'd really love would be a web tool like this with a plugin for actual vim. I currently use a TODO.txt file (kept on dropbox) that I open with <leader>et for my personal task managment. If there were a plugin that would let me edit tasks like Phaser (indentation-based) in real vim, but then could be displayed and further managed by your web interface, I'd love it.