SharePoint 2007 SP2 is expected to be released between February and April 2009 and seems more focused on end-user functionality rather than administration and security, which were the prime domains for previous updates. Among the main areas for the upgrade are performance and manageability improvements to variations in including STSADM commands for repairing links between source and target pages.
The news was first announced on the Office Sustained Engineering blog and later a few more details were released on the Microsoft SharePoint Team Blog. What strikes me as missing based on conversations with the large SharePoint eco-system, including several MVPs, is no mention of improvements in the areas of accessibility and standards or enterprise search.
As our readers may remember, Microsoft has historically been very secretive about the SharePoint roadmap, and I am certain that it has taken many customer requests for Microsoft to become more open and transparent.
Still, I continue to recommend that all buyers keep asking questions directly of Microsoft, as they may be willing to share further details, potentially under a non-disclosure agreement. It's possible that a new feature or bug fix is set for release a few months out, and that could save some time and money on your implementation budget.