I know most of these are heavy lifts, but any ideas around...
...materialized views?
...built-in versioning (Datomic-like)?
...story on how to play it nice with backend languages (One thing MongoDB imo did right)?
Yes, although not in the initial release. EdgeDB _does_ support regular views, which, like the queries, can define arbitrary data hierarchies which can be treated like real object types. This topic deserves a separate blog post.
> built-in versioning
Not planned as a native feature as of now, although that's something that can be implemented on top with the query rewrite system.
> story on how to play it nice with backend languages
Immediately, EdgeDB supports a RESTful protocol with JSON as the exchange format. We will be adding native protocol implementations for major languages as well.