What I really want, and would pay for, is a TextMate or IDE-like interface wrapped around Vim. The current plugins - e.g. NERDTree - are appreciated, but they lack the features, ease-of-use, and consistency of a purpose-built IDE.

I've used various Vim emulators inside IDEs and they're just not the same as the real thing. If you know Vim well, you end up "typing on eggshells", where every keystroke might cause some unexpected chaos. So it needs to be the real thing.