Singleton actor-like compute units
I can see a use for both stateful and stateless units of business logic that are similar to actors, but singletons. I'll call these Units. These would be accessible to clients, Actors and other Units and would be used in a similar way. Some simple examples:
var dateProvider = UnitProxy.Create<DateProviderUnit>();
var date = dateProvider.NowAsync();
var idProvider = UnitProxy.Create<IdProviderUnit>();
var id = idProvider.NextAsync();
This can be emulated at the moment by using Actors, and using Create with a known ActorId to access the same instance.
The benefit of making them a 'first class citizen' is that the code would be clearer, and there is potential for having multiple stateless units active at the same time (e.g. one per node).