I'd like to go a few steps further from your idea. Also, I think 1 event a week would be good.
1. Make it like the blog system. You submit an event, with a description of what it will be about, etc, and an admin will feature it, just as if it were a blog. News / Blogmin would probably be the right admins for the job.
2. After a certain period of time (say the event was scheduled on Saturday, the Tuesday before could be the deadline), all featured events would be voted on by members. This would also have a deadline, maybe Thurday. Then the event with the most votes will take place the following Saturday.
3. The cycle will repeat.
Sorry if all that was a little confusing. I think that it could be a good system of choosing events fairly and regularly each week.
@faRwaY They come around every once in a while. There was actually one just over a week ago. If you're wanting to attend an event, it's a matter of using the chatrooms regularly.