Recently, I stumpled upon Ralf Westphal’s post about packing of .NET assemblies for releasing (sorry, german only). The tool he describes is called Netz and really seems to be useful for having the possibility to break down separate functionality into specific assemblies at development time but not having to deliver a lot of separate assemblies for release.
I did not yet have the time to try Netz by myself. But it is good to know that such a tool exists and will try it out at the next opportunity.