The patterns & practices Windows Phone 7 Guidance is now available on MSDN. 

Learn how to build a Windows Phone 7 application that uses remote services in the cloud.  The guide describes a scenario for Tailspin, a fictitious company, that has decided to use Windows Phone 7 as a client device for their existing cloud-based application.  The guide provides design patterns and explains key capabilities of Windows Phone 7, while walking through the design decisions and trade-offs of  the client application and integration with remote services.

Chapters

• Chapter 1 - Introducing Windows Phone 7
• Chapter 2 - Designing Applications for Windows Phone 7
• Chapter 3 - The Tailspin Scenario
• Chapter 4 - Building the Mobile Client
• Chapter 5 - Using Services on the Phone
• Chapter 6 - Connecting with Services
• Chapter 7 - Interacting with Windows Marketplace

Key Links

• Home Page - http://msdn.microsoft.com/en-us/library/gg490765.aspx
• Code Samples - Download Code Samples
• Community - http://wp7guide.codeplex.com/