Remember the Windows Phone 7 OEM customization and native application development info that leaked a while ago? And the Architecture guide ? Well both documents are now leaked and available to download in PDF format:
The OEM and MO Application Guide for Windows Phone 7 provides guidance on developing applications for a Windows Phone 7 (PDF).
The Architecture Guide provides fundamental technical information about Windows Phone 7. It serves as a roadmap to the components and core fundamentals of the Windows Phone P7 architecture (PDF).
The Customization Guide for Windows Phone 7 provides information about customizing the user interface and other system functionality (PDF).