Topic on Talk:Requests for comment/Localisation format

Couple of big reasons:

1. It moves configuration out of code (and i18n is config, imho)
2. JSON is more portable than PHP and more tools can input/output to it natively
3. Some extensions have FREAKING HUGE i18n files and this will help cut them down to manageable sizes
4. Since extension i18n is now split like core, it's harder for translation updates to conflict with code changes affecting only the en messages

I won't be able to make the RfC meeting tomorrow to discuss this, but I heartily endorse the proposal. I'm sure any rough edges in the proposal can be figured out by the interested parties :)