Scott,
First of all, thanks for your quick replies. You are on the other side of the globe, aren't you? Or maybe I am on the other :-) Anyway, we are probably separated by many timezones and it looks like you guys are always available.
Back to the topic. Since mocks are especially useful in enterprise scenario where there is a need to simulate responses from remote components, it is very likely that access to such components are gained via remoting, DCOM, multiple AppDomains etc. Right now I've found a workaround by writing a proxy object for my tests, but it is very time consuming (and kills much of mock transparency). So it will be great if you can address this.