The Office and MU teams says :
"As we noted when we released Office 2003 Service Pack 3 via Microsoft Update (MU), we are committed to providing at least 30 days notice before making Office service packs available via Microsoft Update automatic distribution (for Vista and XP). Today, we are giving notice that SP1 for the 2007 Microsoft Office System will begin being available via MU Automatic Update starting around June 16th. We released SP1 for Office 2007 to customers approximately 5 months ago and since that time we have had 10’s of millions of downloads and a very good reaction from our customers.