Weighing in on the Wiki/Database discussion.
Many of the Yahoo Groups users have been stymied from finding a new Groups location simply because there was no database/spreadsheet option.
I don't understand Wikis and I didn't use the database personally, (although my members did in MM), but I promise you, if you add a database function, you will win hands down. I can guarantee that, as a 130,000 member group of high school students and twenty-somethings deleted their groups on Yahoo over that loss.
And they aren't the only ones.