This is an excellent question and the answer will change over the weeks to come. We can't make any promises of what inter-node communication will look like right now just because it's too early. We still have some pieces to put together before we can demonstrate clustering in Reactor.
With that said, just because Reactor doesn't do inter-node comms OOTB doesn't mean it can't. :) One would only need a fairly thin network layer to coordinate between Reactors using something like Redis or AMQP to give it some clustered smarts.
We're definitely talking about and planning for distributed scenarios in Reactor. It's just too early to say exactly how it's going to work.
If you need something that does clustering right now, you'll be safer choosing Akka.
