The point of this is that Squid — or most any other HTTP cache implementation, for that matter (because HTTP has a well-defined intermediary role, it’s easy to drop a new one in) — can serve as the basis of what most people think of as an Enterprise Service Bus for HTTP. True, it doesn’t support any WS-*, but more people are considering that a plus, not a minus, and you don’t have to pay a vendor for the privilege of debugging their beta product; it’s free and battle-tested. Oh, and a hell of a lot faster.