Well, it doesn't get much simpler than JSON over 0mq. I think Mongrel2 will actually have to include some turing complete language since there's no way I could anticipate what people will want to modify with it. If there's one thing I know, it's that companies do the craziest stupid crap with their architectures.

As a side note, the current design is definitely POC level, so keep tracking it and if it goes off in a stupid direction let me know.