Message filtering on event bus

The event bus currently provides interceptors, but there are situations where to intercepting a message is not enough and it would be really useful to be able to prevent a consumer from getting executed and maybe replies can / should be produced on a central point.
IMHO the event bus is a really proper alternative to rest as general communication solution, but e.g. authentication / authorization is one of the missing features. I think such a possibility to filter message would be a good base to solve scenarios like that and may others as well.