Download and install Windows Phone 7 Developer Tools April 2010 Refresh.
Note as part of this install I had to remove the following components in order:
- Microsoft Visual Studio 2010 RC
- Microsoft Windows Phone Developer Resources
- Microsoft Windows Phone Developer Tools
- Microsoft Silverlight 4.0 SDK
- Microsoft Visual Studio 2010 Express Prerequisites x64.
- NET Framework 4 Multi-Targeting Pack
- Microsoft .NET Framework 4 Extended
- Microsoft .NET Framework 4 Client Profile
- VC 10.0 Runtime
- Microsoft Windows Phone Emulator x64
- Windows Phone 7 Add-in for Visual Studio 2010 – ENU
- Microsoft XNA Game Studio 4.0
Ever had one of those days when your mouse batteries go flat in the middle of a blog post. Then you swap out one of the batteries from the mouse and switch it with the keyboard to suck the last remaining juice from it. Ten minutes later both are flat and you got no spares. Lets just say its one of those days 
Anyhow the refresh has new features (-take note of the additions to the emulator ) and breaking changes(download release notes at this link) - take note of the new publisher setting and notification templates.
