lexically-scoped type variables in GHC 6.6

With reference to the documentation that just appeared in darcs: Result type signatures are now equivalent to attaching the signature to the rhs, i.e. redundant. How about finishing the decoupling of type variable binding from pattern type signatures by introducing an (optional) pattern form forall v1 ... vk. C p1 ... pn mimicking the datatype declaration for an existential (with vi scoping over pj, guards, where decls and the rhs), so the example would become data T = forall a. MkT [a] k :: T -> T k (forall a. MkT [t]) = MkT t3 where t3::[a] = [t,t,t]