Microsoft has released Exchange 2010 SP2 RU6 and Exchange 2007 SP3 RU10 today neither of which gets any closer to supporting Exchange 2013.
Direct links to downloads:
2010 SP2 RU6 - KB2746164
2007 SP3 RU10 - KB2788321
As always it is a good idea to test these updates in a lab before applying them.
UPDATE: Although not mentioned on the download or information pages Exchange 2007 SP3 RU10 does allow for Exchange 2013 coexistence although you need to wait for 2013 CU1 as per this blog post: Exchange Team Blog