Is this in any way related to Requests for comment/Redo skin framework? If not, it probably should be merged into there. :)
Topic on Talk:New skins system
This page seems mostly focussed on:
- Remove skins that maintainers of MediaWiki don't want to maintain
- This is mostly done at this point.
- Provide simplified installation mechanism (e.g. Special:Administration/plugins with GUI search, and one-click install/enable).