I have an decent excuse for not reporting this earlier.
I had 4 infected and impacted wisdom teeth removed this morning. As strange as it sounds, I haven't felt this good in a long time. I suspect they had been bothering me and festering for a long time.
With that out of the way, I recommend installing this rollup as a precursor to Exchange 2007 SP1.
The fixes include:
KB 930463 - You receive NDR messages for some recipients when you send e-mail messages on an Exchange 2007-based server
KB 937656 - You experience problems in Outlook Web Access for Exchange 2007 after daylight saving time (DST) starts in New Zealand in 2007
KB 936300 - A mailbox move operation stops responding when you move a mailbox from an Exchange 2003 mailbox store or from an Exchange 2007 mailbox store to another Exchange 2007 mailbox store
KB 932561 - Appointments that are sent from one Exchange organization to another by using Exchange 2007 may be incorrect by one hour if one organization is in the Western Australia time zone
KB 937861 - You receive a non-delivery report (NDR) message when you try to send an e-mail message to a third-party connector address by using a third-party connector on an Exchange 2007-based computer
KB 938359 - The Microsoft Exchange Information Store service stops responding in Exchange 2007 after you enable the Standard Response option on a moderated public folder
KB 940052 - Error message when you use the Exchange Management Console to try to reconnect a mailbox to a user account: "The specified mailbox is not unique on database"
KB 933314 - Mobile devices cannot send e-mail by using the AirSync feature in an Exchange Server 2007 organization that has more than one thousand accepted domains
KB 939560 - Users cannot download offline address books in Exchange 2007 when you use Microsoft Solution for Hosted Messaging and Collaboration version 4.0
You can download it directly from here, and read about the changes here.
By the way, Elan has a good writeup on Exchange 2007 SP1 and Windows 2008 over here.