I don't believe that is officially supported.
I do a have a customer who is using it for the Archive share but only writes from one location.
I would be careful trying to use it for Index and Message Center due to the potential performance issues.
Writes to more than one location would also be an issue in a distributed environment.
I am not sure if EMC would have tested DFS exclusively. I do know some customers are using DFS due to their own justification. As Gary mentioned you need to be careful in the design especially round performance issues.
Here is an article that was once suggested for DFS.
Basically all you need to make sure that shares are always available and there is no performance issues.