Wiki's are very cool. It seems to be very easy to use and for teachers that's a big plus. I like the fact that it anyone can add new content, which only encourages students to be life long learners. However, I can't help but have a bit of an uneasy feeling as well....All you need is one goofball to ruin it for everyone. So if it can be tightly monitored, or secured in some way that will make it safe for everyone, then I'm all in favor of it.
I would like to have a wiki page for grade level teachers. Maybe one page per grade level, where as teachers we can share, and post new activities and experiences. It's so hard for me to keep up with all the new changes, that I'm sure that I'm not the only one. So maybe a Wiki page for teachers would be awesome place to ease teachers in.