That's good to know. And Socket.IO could move back to WebSocket-first approach, once the technology becomes more pervasive. It's still a task to set up Socket.IO with Python though. Don't know how nice it plays with Node.js, but I'm happy moving to Go instead.
Socket.IO works the other way around since v 1.0, thanks to Engine.IO. It starts with long polling and tries to upgrade to WebSocket or Flash sockets if possible.