Something I don't see talked about too much, but what I think could be the most exciting thing about the Firefox phone, is that a web app (hosted on the web) could have full access the the dialer, sms, camera, and all of a phones capabilities.

I think then you might see a whole range of independent homescreens and app suites developed and offer some well designed alternatives.

I'm a nexus 4 user and I really don't like all the basics. The dialer, contact list, messaging. I think they are confusing and difficult to navigate.