Visual Studio 2010 is missing a number of extensions that are automatically included as part of Visual Studio 2012, so please use Visual Studio 2012 whenever possible. If for some reason you are forced to use VS 2010, then you will need to follow the instructions below to update VS 2010 so that it will be suitable for the development required.
This is a quick guide to updating Visual Studio 2010 in order to enable it to create and edit SQL Server Express local databases. DMU switched from MS Access to SQL Server this year for the first time, and it has caused serious compatibilty issues. It would seem that Microsoft stopped updating the Server Explorer in Visual Studio so that only SQL Server 2008 and earlier databases can be edited. See SQL Server for a guide to installing SQL Server 2012 Express and the Management Studio.