Found via the Kept-up Academic Librarian, the latest in the Educause series of "7 Things You Should Know About": 7 Things You Should Know About Collaborative Editing Tools (2 page PDF). Collaborative Editing Tools include things like wikis and Writely, but this factsheet doesn't mention any tools by name; it starts with a scenerio and then moves on to discuss the following topics: 1) What is it? 2) Who's doing it? 3) How does it work? 4) Why is it significant? 5) What are the downsides? 6) Where is it going? 7) What are the implications for teaching and learning? Very nice way to get up to speed.
Incidentally, some of the other topics in the 7 Things series might be of interest to you as well: Instant Messaging, Augmented Reality, Blogs, Video Blogging, Wikis, Podcasting, Clickers, Social Bookmarking.