The Windows Phone 7 Developer Tools Beta version have just been released and are available for download now.
After the CTP first shown during MIX10 in March and a refresh in April it’s now time for getting your hands on the beta. If you have the previous CTP version installed, make sure you read the installation notes and uninstall the previous version. There are also breaking changes, which I recommend reviewing as well.

This is one single download that installs the following tools, as always completely free:

• Visual Studio Express for Windows Phone (it will install as an add-in if you have VS2010 RTM installed)
• Expression Blend 4 for Windows Phone – this is version of Blend that only works for Windows Phone projects, and yes totally free. It’s actually the only Expression Blend release that is free.
• Windows Phone Emulator
• XNA Game Studio 4.0

For full coverage and background info, developer device availability, and a virtual training please see the Windows Phone team blog post.

Upgrading your CTP project: to upgrade your project, nothing better than this extensive post by Jaime Rodriguez: Migrating apps from Windows Phone April CTP Refresh to the beta build.

So, what are you waiting for?

Have fun!