As the author of xmpp-ftw I feel I should throw some comments into this discussion.
Firstly, xmpp-ftw is not about starting an XML/JSON holy war, its about lowering the barrier to entry as far as possible. So see it as more of a gateway drug :) *
At present the tiny amount of effort it takes to build a proprietary (legacy) chat system with other technologies means that XMPP is somewhat being left behind (on the web) despite offering a huge number of benefits. Xmpp-ftw tries to make it as easy as possible by providing developers a format they are comfortable with and the ability to send/receive data with the minimum of fuss.
This project actually came out of discussions at XSF summits I've been attending. No-one (myself included) believes that XML should be replaced with JSON in XMPP, that would be a foolish notion. Generic JSON <-> XML is awful and doesn't quite work. The idea with this project was to used named events to fill in some of the missing information for building stanzas, and telling the user what is happening.
The view of JSON with XMPP has changed over the last couple of summits has changed, going from being referred to as the J word' through to open discussions about what can be done (the XSF seems like a very progressive group). No more jokes about XEP-0295 :)
If you want to see a better client library trying to do something similar check out Lance Stout's stanza.io https://github.com/legastero/stanza.io which came out of the same meeting.
So in summary: Xmpp-ftw is attempting to drop the barrier to entry for XMPP as far as possible and make it quick and convenient for developers to implement. Its not about replacing the angle brackets :)
Cheers, Lloyd
FYI, yes I've used socket.io, but you can stick anything that implements an event emitter and has callbacks and have it work. Currently I'm looking at wrapping sockJS.
Having broken both wrists in separate accidents 2 years apart (ORIF distal radius fractures with plates installed) I know where you are coming from with this (also cycling accidents).
If your injury/treatment was like mine then in all honesty its not something worth worrying about, you'll be able to pick up typing with a single hand fast enough and after a couple of weeks you'll be able to use fingers to hit things like shift key (as a developer you'll still be able to type faster than 90% of the company!).
Over time you'll find you'll be able to do more and more typing with the injured hand, and by getting blood flowing through it via usage it'll probably help the healing process.
If you want to ask any questions feel free to contact me via twitter/email/etc.