Don't we have this already? What has happened to Wikidata?
What is Wikidata failing to do? Why is this needed?
What will SDAW provide to solve that?
Topic on Talk:Structured Data Across Wikimedia
The SDAW section topics will use Wikidata items to describe sections of text in Wikipedia articles. There is no intent to replace or supplement Wikidata. Whereas we already have Wikidata items attached to articles at the highest level, this will attach them to sections of text.