I can't see any reason you can't do something like:

    class MetaDec(args, here):
        ...
        def __call__(self, func):
            # Decorate function here

    def meta_dec(args, here):
        return MetaDec(args, here)

    @meta_dec
    def decorated:
        ...

(apologies for any syntax fails, python is not my best language)

At which point one would imagine you can abstract out the __call__ part and just have a 'decorate' routine on any class designed to work what way or similar.

Whether this is an improvement or not over closures almost certainly depends on the use case, of course.