There is certainly room for better wiki options. I found JotSpot to be the most interesting and innovative, but it basically died when it was acquired. The current offerings are so heavily weighted toward power users wider adoption simple will not happen (in terms of editors).

I've had the chance to work at a large scale website based completely around a wiki, and the successes and failures therein became quite evident. There is definitely room to innovate, especially on the editing side of the experience. I have some interesting friends in the wiki community, so feel free to ping me if you want to chat about it some more and I can probably put you in touch with them.