I have two multi-author blogs:
Let's Sermo- Here I just have friends who post. This is not revenue sharing. On this blog I earn almost 400$ a month.
The Blogging Park- This is a blog, where all profits are shared. It is doing terribly. Here people say, "He has not yet posted, so why should I".
At the end of the day, all that matters is who is on your team.
Also, I have The Dollar Diary. Here I am with Swas, and the blog is doing very well as Swas and I sync, and there is no blame game or anything at all.