You topic/query has been discussed on the SAS forums before - suggest you search the archives. Also, there is "Excel version support" information on the SAS.COM support website at
http://support.sas.com/ either using SEARCH or possible a Google advanced search argument, such as:
excel version 2007 support site:sas.com
Also, you will need to consider that SAS version support and related Excel version support may not generate an actual Excel 2007 format file for you, however you do have some options.
Scott Barry
SBBWorks, Inc.