Today I added a new page to my website for Windows Phone 7 developers.
It’s a compilation of all of the best tools, tips, controls, demos, and sample code that I’ve found…all in one place. You can check it out at:
http://jeffblankenburg.com/wp7
Bookmark it, because I’ll be adding to it over the next 12-18 months. Also, if you didn’t hear yesterday, the RTM edition of the WP7 tools was released. Check em out at http://developer.windowsphone.com!
JEFF BLANKENBURG 
These are also good lists:
http://indyfromoz.wordpress.com/windows-phone-7-resources/
http://blakehandler.wordpress.com/2010/04/05/ultimate-list-of-free-windows-phone-7-software-resources-from-microsoft/