Microsoft has released Windows Phone Developer Tools CTP

The same powerful and easy to use Visual Studio integrated developer environment (IDE) handles from design to testing of Windows Phone 7 Series phone applications.

The Windows Phone Developer Tools CTP includes the following

Visual Studio 2010 Express for Windows Phone CTP
Windows Phone Emulator CTP
Silverlight for Windows Phone CTP
XNA 4.0 Game Studio CTP

Windows Phone Developer Tools CTP