Have to agree about the lack of inheritance - it's the best thing about Go is avoiding all that abstraction that people pile on top of simple concepts, leading to logic being spread around lots of different files. You can go a long way with just structs and functions.
Nice to see them being open about this project, they have a lot of people involved but I'm not sure they're solving real problems yet - surprised it's taking so long to converge on something actually usable, given all the prototypes in previous versions. Here's what I want from dependency management:
Freeze current deps to vendor
Save deps using semantic versioning
Let me edit versions to things like 1.x to allow all version 1 updates for deps I trust.
That's it. I don't really care about diamond dependencies yadayadayada because I can just solve them myself. Yes eventually tooling for that is nice, but it's not even a problem most people will hit initially.