Good point. I sort of lost contact with the Plan 9 world a while ago -- I kept following the news, but no longer ran a system. Last time I used it, the X11 port was somewhere between experimental and broken, and vim is, uhm, not the editor whose port I'd be interested in :-). My comment is certainly not up-to-date.
Edit: I share your point about the lack of need for either ncurses or vim (especially vim, hheheh). My first contact with Plan 9 was somewhat disappointing, mainly due to the fact that I approached it with the oh, Unix, I know this! frame of mind. I was very much a Linux fanboy back then (did I mention it was in highschool? And this is not the dumbest thing I did in highschool!). Only after I studied the source code a little, and learned rc more seriously, did I really begin to appreciate it.
There is also an ncurses port and a vim port. I don't feel the need for either of those.