Starting with SQL Server Denali (at least in the community preview version with which I installed the game), SQL Management Studio is integrated into the Visual Studio 2010 development environment. This way you get all the syntax highlighting, Object Explorer, etc. All from VS2010.
However, I didn’t specifically try to add an SQL script to an existing project (and last week I removed common functions because there were ... problems), but with such tight integration, I suppose more or less what you are asking for is an intention.