All of my Then methods end up with a single "Assert.True(condition);". I'd like to turn that into "return condition;". I see a number of advantages.
First, it would help remind me that I need an assertion. Sometimes I forget that line. By making it a return type, the compiler could help me.
Second, I wouldn't need to take a dependency upon any particular unit testing framework. It turns out that the only method I need from these frameworks is Assert.True.
Third, NBehave could do something intelligent with "not". If it finds the word "not" in a "then" phrase, then it could Assert.IsFalse. As it is now, I have to include a $not parameter.