We don't yet have a standard for XMPP over WebSockets that the servers can implement, which will be required before the client side can be tackled adequately.
The first step is to finish WebSocket standardization. It looks like this may happen in an IETF HyBi working group, which at the time of writing has not yet been approved by the IESG. There was a HyBi Birds-of-a-Feather (BoF) at the Hiroshima IETF meeting a couple of weeks ago (see the meeting materials), which went pretty well.
After WebSockets has a stable reference, and seems to be settling down, the XSF will create a XEP that binds XMPP to WebSockets, presumably with a stanza per WebSocket frame.
Edit: Jack Moffitt has written an IETF Internet-Draft with a first pass at a protocol that can be used. WARNING. This is still likely to change drastically. Only implement it if you're willing to rip it out completely later. WARNING.
