By allowing the resolved method to be called with a bound this, it would allow one to implement the Builder pattern without having to pass all dependencies as method parameters (because this is undefined). At first glance this could be accomplished by fixing instantiate.js's instantiate function to provide a this arg in the invocation of apply:
begotten = ctor.apply(undef, args);
I also tried to use the invoker factory, but there some spookiness going on with regards to promises...