In order to keep up with the development of the platform as well as to help developers publish their applications more easily, Microsoft has updated the Windows Phone 7 Application Certification Requirements — pretty much the same way they did back in October.
The recent changes bring significant improvements meaning the requirements got clearer (several content policy and technical requirements have been clarified), contain in-house-like test steps to improve overall pass rates, and became more usable by becoming integrated with core developer documentation on MSDN. Additionally, they’ve been migrated to a new HTML-based format which should deliver easy access to information.
The new Application Certification Requirements become effective June 3, 2011 and some of the changes ads, privacy concerning location data, updated rules regarding not allowed content, and many more. Follow the source link (3) for a complete list of changes.