Using netjack to connect two or more computer running jack is nice. But netjack is compatible only to netjack...
One of the most promising protocols/technologies for the future digital-audio routing is named ravenna which uses only already established protocols to feed audio over IP networks in realtime with a defined latency and sample-phase accuracy. On the long run this should be supported for the jack-audio-connection-kit.
On the short run I am currently looking at ccrtp and playing around with it to write small jack-streaming apps to send and receive data via rtp...