>SWAG - can you run it under SvcHost? http://en.wikipedia.org/wiki/Svchost

This is a route I would really want to avoid because I have seen so many people trying to workaround using that approach and that creates additional issues.

And, yes, as is, from a DLL, it won't work.

However, the topic is popular. Lots of people want to host the base class inside a DLL. It makes sense. All framework are DLL based. There has to be a way to achieve that in a simpler way.