The recently announced April Refresh for the Developer Tools CTP now supports the RTM of Visual 2010 so you can go get a copy and start coding your way to Windows Phone 7 application stardom!
Couple of gotchas though, before you install the Developer tools you will need to uninstall the Silverlight 4 SDK, otherwise the install will fail and, Contrary to Charlie Kindles (Windows Phone 7 development product leads) explanation at Mix this year, the development tools installer automatically installs Visual Studio Express 2010 for Windows Phone 7 as well, NOT just adding the tools to your VS2010 installation, so you will need extra space for the install.
You can download the Developer Tools here:
http://developer.windowsphone.com/









