V3.0 of the Facebook Developer Toolkit was just released on Codeplex.

Major Updates:

• Provide better doc and samples
• Provide support for Silverlight
• Provide support for ASP.NET MVC
• Provide improved support for WPF
• Provide improved support for FBML (FBML Server Controls)
• Provide a login control that can be used to replace the BasePage and/or MasterPage for Canvas Development
• Improve out of the box support for Extended Permission Prompts
• Refactor core source to improve maintainability and design
• Fix known bugs