Alright, we're close to issuing this code in production for the Wikipedia Zero end user use case.
Federico, you're right -
www.wikipedia.org/ gets a lot more traffic than
m.wikipedia.org/;
www.wikipedia.org/ skews more toward English, for several reasons, but it still seems like wiring up a JavaScript widget to talk to an API that examines the Accept-Languages, or something like that, might be useful for multilingual users and users not reading a language listed toward the top of the page. I'm currently pretty busy, but we could maybe at least ask Mxn (if not on this list) what Mxn thinks, as Mxn has been pretty involved with the global Wikipedia portal template. Should I BCC Mxn on this thread, or email Mxn off-thread? Mxn tries to avoid spam from what I can tell on Mxn's personal website.