I'm afraid there is no turn based multiplayer example yet available.
Maybe with the C2 comp, who knows ?
As far as the realtime multiplayer goes, the HTML5 implementation of websockets wasn't completely over. The browsers have yet to imrove it and enable it by default in their configuration first before it can be considered as fully usable.
Moreover, server side will have to be programmed in a "true" coding language.
It's likely that this step will take a bit more time.
For now it is better to learn and make single player games, or asynchronous game (turn based, yet there's no example yet but you can always take a look at the AJAX tutorial or this topic which are pretty much the ways to go.)