Amazon offered this today:
Kindle Worlds fro Authors
What this breaks down to, in a nutshell, is work-for-hire in worlds that Amazon winds up with rights to. So far that includes the VAMPIRE DIARIES. and a few other properties. I suspect there will be more.
There are pros and cons and author John Scalzi does an excellent job of examining the situation in a preliminary way. So good in fact, that I'll just leave this hear for anyone that wants to consider the idea.