Hi,
Continuing yesterday's theme of deciding about fonts for projects in many languages, I wrote a page about the desired first step in that direction: https://www.mediawiki.org/wiki/Internationalization/Styling_and_typography
The rest of the Localization team supports me on that.
TL;DR: Before writing a big new movement-wide style guide we must understand and document the different content and UI elements that need styling in different languages and communities and only after that start to bikeshed about particular fonts, weights etc.
Comments about that page are welcome.
-- Amir Elisha Aharoni · אָמִיר אֱלִישָׁע אַהֲרוֹנִי http://aharoni.wordpress.com “We're living in pieces, I want to live in peace.” – T. Moore