resolve an issue that prevented files from copying to Windows file servers
resolve issues with recurring events in iCal when connected to an Exchange server
printing reliability
synchronization of the "Sent" mailbox on a Microsoft Exchange server
properly warning mobile users in an Active Directory domain about upcoming password expiration.

and mobileme does not look to work at all with 10.6.3
Ah so it isnt just me who has had trouble with mobileme. This was before the update this evening