Allow Injection of custom primitive serializers into existing Seralization Stack

I would like to be able to allow for custom serialization without having to replace the entire serialization stack. This would be relatively easy to do except that the relevant classes are sealed and there's no hook to modify the static list of serializers used by default.

For instance, if I want to replace the DateTime serializer, or the Int64 serlializer I want to be able to add that into the existing stack. I do not want to have to completely replace the entire stack.

See here;

http://stackoverflow.com/questions/12201812/mongodb-override-default-serializer-for-a-c-sharp-primitive-type