I've been wanting vim support on the iPhone for a while.

I actually think it's a big thing that would work well on the iPhone. The whole point of vim is that, with only a few keys, you can navigate anywhere you want extremely quickly. Most of the limitations of the iPhone are things like "can't see many keys at once", and "hard to go to specific lines by dragging your finger around the screen", etc. Vim on the iPhone can fix all that.

Haven't seen this app though, off to play with it. Hope they did a good job :)