Please check out this Microsoft Channel 9 presentation, and this walk-through here.

As a FIM identity guy, the reason I’m so interested in this is that it suddenly means that the integrity of user properties changes from being “nice to have” (useful meta data about a person) to a security dependency for the organisation (i.e. you can’t set up a DAC on a folder such as “all users in department x have access to resource y” if you can’t rely on the integrity of the department property :).