Microsoft ranks Windows 7 features most likely to affect app-compatibility | All about Microsoft | ZDNet.com
While Microsoft officials have said that applications that work with Vista should work with Windows 7 , there are exceptions.
The 45-page “Windows Application Quality Cookbook” (Version 0.9 of which Microsoft released for download on November 3 on its Microsoft Developer Network site) itemizes some of these potential gotchas in the hopes of getting developers to head off problems sooner rather than later.
an excellent source of information for Windows 7 especially for developers