I have no doubts your system is a very powerful and scalable solution for pubsub, but I believe just the fact that it's not utilizing Websockets, the overhead is not acceptable for MMOs or other latency sensitive tasks. So you shouldn't advertise as such, people might actually believe you and try and build one. It'll blow up in their face when they realize they can't get the latency down to an acceptable level due to the 200-300 extra bytes per request and the delay of constantly opening new connections.
There are a fair number of browser based strategy games such as evony.com where latency is not really an issue. It's mostly a question of how to handle communication between back end servers and 'world' chat that's the real scaling issue.
It should be more than adequate for strategy or turn based games. Perhaps I should have been more clear that I was talking about latency sensitive MMOs, like shooters or anything where your position and movement in time are critical to the gameplay.
