The Office Sustained Engineering team has just released the official date for shipping Office 2007 SP2. This will be released to the web for download on Tuesday, April 28, 2009.
More details on what is being addressed in SP2 can be found here on their blog post.
Also, just a reminder that mainstream support for Office 2003 ended earlier this week. More details on the Office 2003 support lifecycle, and reasons to consider upgrading to Office 2007, can be found on my earlier blog post here.