I have seen questions in the forums and blogs before regarding the possibility of federated active directory security coming to Microsoft Dynamics CRM Online for some time now, but it sounds now like Microsoft has committed to a date. I first caught wind when I read this post (http://community.dynamics.com/product/crm/f/117/p/54548/98341.aspx), but figured it would still be awhile before it happened.
Then about a week ago, at the very first CRMUG meeting for the new Minnesota regional chapter, a Microsoft Employee that works specifically with CRM came out and said that it would be coming this year yet in Q4 along with a bunch of other feature enhancements that are going to be part of a first round of enhancements that is going to become a regular cycle as Microsoft is trying to move away from the big upgrades every 2 years or so in lieu of having more incremental enhancements on a more regular basis (maybe a couple times a year).
How about that! I am excited! Look out SalesForce. :)
Update! - I guess now it sounds like even though the linked "What's New!" document doesn't show it http://bit.ly/uHWumO It sounds like MSFT will be offering this to clients on a one by one basis starting in November.