The deployment engine is two .NET assemblies, one core and one provider assembly.
However there is no direct way to run managed custom actions from an installer, which is what you would have to write to make this work. The reason why the installer folks do not like this is the unexpected behavior if you load mixed version assemblies from the same host.
The supported way will be to run a command line version from a custom action in WiX. We will provide a command line shell, vsdbcmd.exe, which will be able to deploy a .DBSCHEMA file. I will be demonstrate this on Friday at TechEd in my session TLA320.
-GertD