Microsoft announced the second service pack for Office 2007 will be published this month, it will be available to customers via direct download, Windows Update/Microsoft Update, and Windows Server Update Services (WSUS).
"Service Pack 2 for the 2007 Office System will be made available in April," a posting to the WSUS product team blog reads. "Service Pack 2 includes some significant work, including: built-in ability to save as ODF and PDF formats, improvements to Outlook's performance and calendar reliability, significant bug fixes for charts in core Office applications, the ability for client service packs to be removed using an uninstall tool, and a host of customer-requested improvements to the Office Server products. It is also a rollup of all fixes that have previously been released for Office 2007 products."
The next version of Office is named Office 2010, it's expected next year.