Dynamo seems to be still pretty early in development. You might want to watch the video linked to the page from the 0redev conference. He doesn't talk about dynamo much, but he does give "2013" as the date for Dynamo.
On the WebSockets issue, I'd check out Cowboy. Cowboy seems to be the new hotness in erlang web apps. It has at least some support for web sockets.
If you're looking for a full featured web framework with built-in web socket support then maybe what you really want is Nitrogen: http://nitrogenproject.com
Finally, and just for completeness, since I'm mentioning web frameworks, you'll probably want to see what ChicagoBoss's WS story is: http://www.chicagoboss.org or if someone's done something with WebMachine and websockets: http://basho.com
I think Nitrogen sounds like the best bet.
Since Elixir seems to mix effortlessly with Erlang, you should be able to write your code in Elixir using any of these frameworks.
I usually really don't like huge web frameworks like Nitrogen. I'll take a look though.
Edit:
Took a look at the documentation. You couldn't pay me to touch Nitrogen. Hopefully Cowboy turns out to be more promising. I'm already familiar with CB.
On the WebSockets issue, I'd check out Cowboy. Cowboy seems to be the new hotness in erlang web apps. It has at least some support for web sockets.
https://github.com/extend/cowboy
If you're looking for a full featured web framework with built-in web socket support then maybe what you really want is Nitrogen: http://nitrogenproject.com
Finally, and just for completeness, since I'm mentioning web frameworks, you'll probably want to see what ChicagoBoss's WS story is: http://www.chicagoboss.org or if someone's done something with WebMachine and websockets: http://basho.com
I think Nitrogen sounds like the best bet.
Since Elixir seems to mix effortlessly with Erlang, you should be able to write your code in Elixir using any of these frameworks.