Kim Cameron, one of our key identity architects had an interesting presentation on identity in the cloud and a corresponding interview. Both are worth looking at if you are planning to move into the direction of the cloud. Especially as it is definitely one of the key challenges:
This is Kim's presentation: Video
If you want his slides, here they are.
And finally he was interviewed after the presentation. It gives you more insights into our thoughts around identity and identity federation: Interview
Remember, from my point of view, identity processes, management and federation are key ingredients for a successful cloud strategy
Roger