another bytecode interpreter ?

Depends on what you mean by "striking". I find that current server CPUs are 3-5 times faster at single-threaded workloads than 8-year-old single-core ones. Every generation of Intel processors still has performance gains of 10% or so while consuming less power.

I see your point about the overhead of complex protocol encodings. But if we go back to the original topic of firewalling: increasing network speeds would not be such a big problem if we weren't still be stuck with packet sizes that were designed for 10 Mbps networks.