Office 2007 SP2 includes support for the OpenDocument Format, an open standard backed by many companies including IBM and Sun Microsystems but initially resisted by Microsoft.
Customers who download the service pack will be able to save documents in ODF and Adobe Systems' PDF, just like they would any current supported file format in Office. They can also set ODF as the default file format.
Office 2007 SP2 will also natively support PDF. Adobe initially opposed Microsoft's decision to add PDF to Office, but has since made PDF an open standard.