After official launch of Visual Studio 2010 in Las Vegas, Microsoft has highlighted incompatibilities of Visual Studio 2010 Express for Windows Phone CTP (Windows Phone Developer Tools) with Visual Studio 2010 RTM. If you install the retail (RTM) release of Visual Studio 2010 on the same machine on which you already have the Windows Phone Developer Tools CTP, you will be unable to build your Windows Phone projects. Further, while the Windows Phone project type will continue to appear in the File/New dialog, you will not be able to build Windows Phone 7 applications. The current CTP is based on