The VSData team blogs about new database features with SQL Server Express and Visual Studio 2005. Apparently when an SSE database is added to the VS project and the project is built, the MDF gets copied to the build directory along with the EXE. When the application runs, the framework automatically finds the MDF in the application directory.
This sounds great for quick and dirty development. But is it really what you want when building a real application? If the application is installed into the Program Files directory, non-admin users won't be able to edit an MDF in the application directory (I'm assuming that the MDF doesn't just hold static data here). Aren't applications supposed to use the “Application Data” or “My Documents” folders for this kind of information? Is it just as easy to deploy the MDF to an AppData directory and have the framework automatically find it there? Do VS installer projects know how to automatically deploy MDFs to an AppData folder?
I haven't installed SSE/VSb1 yet to try it for myself. But right now this isn't sounding like a “pit of success” feature.