A while a go I was wondering why Windows 2008 R2 wasn’t enlisted in the list of supported management agents for Active Directory services. This list can be found at http://www.microsoft.com/forefront/identitymanager/en/us/faq.aspx and now actually include Windows 2008 R2.
So I asked this over at the activedir.org mailing list and Thomas Onyszko came with the following answer on his blog “Tomek’s DS World”: FIM and Windows 2008 R2 AD support
Recently some updates were released for FIM (KB978864) which have up till now no associated KB article (still going through review I think) but yesterday Thomas posted an update on the subject: Windows 2008 R2 recycle bin support for FIM.
Bottom line:

• Install KB979214 on your DC’s
• Install KB978864 on your FIM servers, available through windows update or the update catalog
• Enable/Use recycle bin!