I havent played with Unity for a little while now, but I have fond memories of the Cartographer project and the then upcoming Unity 3. With Unity 3 now doing great things, it is fun to see products like Mixamo support the engine. Mixamo supports much more than just Unity, but that was how I came across the tool.
Mixamo is a set of tools to help compose, manage and apply animations to characters in a range of software. Here are videos showing this off in DAZ Studio and Unity:
I noted that on 3DBuzz there is a full course using Unity in the creation of an MMO no less by Jason Busby. Check the site for all the details of the MMO online course.