The EHLO blog folks posted an interesting blog entry on some upcoming changes for E-12 that change how you provision users and also changes to the recipient policy mechanism (the RUS dies) and hurray, it looks like they might have gotten a clue with the property sets and put the Exchange attributes into Exchange specific property sets (something I have been asking for since first seeing E2K up close at least 4 years ago).
This is going to be pretty huge for many large orgs that have “rolled their own” provisioning systems that operate by modifying LDAP attributes and then wait for the RUS to finish the stamping. Hopefully the programmatic methods that will be available are simple and fully available CROSS PLATFORM. If everything they did requires MONAD and NET and a Microsoft machine to do the provisioning they really screwed up because not everyone provisions from Microsoft machines.
http://msexchangeteam.com/archive/2006/08/24/428754.aspx
http://exchangeninjas.com/OPATHSyntaxforDynamicDistributionGroups
That would answer that question, no?