I love Babel templates. They are great to express what languages you are familiar with and what level of confidence you have when using a language.
Babel templates are used on many projects. On OmegaWiki, my home wiki, it is required of the people who want to edit. There is one nuisance with Babel templates, there are a lot of them and, it is hard to get all the texts that make up the templates.
MinuteElectron is changing all that. He made it an extension. Given that it is being developed first at Betawiki, adding the messages is easy and obvious. The messages are stable, so while the software is being finetuned, the localisation has already started.
One of the clever things in the code is that data of different standards is used to make up the total number of languages. Both ISO-639-1 and ISO-639-3 codes are used, information from the CLDR is also considered. It is now a matter of finetuning the code and selecting the languages it supports.
All in all, a great new extension is being developed.