Have you seen the http://www.readyset7.com/ site for hardware and software manufacturers preparations for WIndows 7?
It's a comprehensive site for ISV and IHV developers to help in the effort to ensure compatibility with Windows 7.
Partners can get more info on the Windows 7 Ecosystem Readiness Program to access Windows 7 builds, support, and toolkits. We also make available new white papers and documentation via the WHDC Developer Tools Site and much more.
ISVs can leverage the Windows 7 Application Quality Cookbook helps you verify the compatibility of your applications. It discusses the few known application compatibility issues in Windows 7, points out differences in performance, reliability, and usability, and provides links to detailed white papers and other developer guidance. Also review the Windows 7 software logo requirements.