If you have a frequently asked question (FAQ) about Active Directory Rights Management Services (AD RMS), you will definitely want to start check out the updated AD RMS FAQ on the TechNet Wiki.
Check it out at: http://social.technet.microsoft.com/wiki/contents/articles/ad-rms-faq.aspx
And please feel free to review, contribute to, and update this FAQ article if the mood strikes you to do so. Thanks to Enrique Saggese who answered the vast majority of these questions, former AD RMS writer Jim Groves who collected most of them, and Kurt Hudson and Brad Mahugh for driving this forward.
The FAQ is our main place to consolidate the questions (and the answers to them) that we hear that IT professionals are running into when it comes to AD RMS.