I'll get around to looking at this language more seriously over the next couple of days. I hope there is a way to cast types (generics for instance) to other types without having to either implement an interface or walk an instance of the type to create a memberwise clone. If not then I'll still be happy.

Sure, the casting operators (:> and :?> - that's colon-greaterthan and colon-questionmark-greaterthan, in case they get mangled) work with class hierarchies just as well as with interfaces. I'm not sure how creating a clone comes in with casting, but I hope it helps anyway :-)