I just opened up this repo yesterday: https://github.com/stripe/aws-go.
It's really raw, but it uses the JSON API descriptions from botocore to generate Go clients for all 40 public AWS services.
1. Announce something in a blog post (sometimes get everyone really excited)
2. Add access to that feature/setting in the AWS Web UI
3. Add access to that in the official API
4. Add access to that in aws-cli
5. Add access to that in cloud formation stack creation
But you're right, maintaining even a blessed third-party library like boto is a massive undertaking: 437 contributors, 431 open issues, 192 open PRs. Competing against CloudFormation using anything other than the Java client library is crazy IMO.
But anyway, goamz is "Hashicorp's" AWS Go SDK in that Hashicorp forked it and refused to work with the larger community because it's "critical" to their business. This has, at least until super recently, stranded certain functionality into the different forks and severely fractured the AWS Go offerings. True story.
Ultimately, what the Go community probably needs most is Amazon to step up and support a Go SDK officially. The Java, Ruby, .Net, and even Python SDK's are very robust at this point. I can't speak to the others.
IMO the best of the AWS libs is github.com/bmizerany/aws4. It only wraps the auth, the API and results are up to you. This requires more work but means you never have to worry about the lib keeping up with the API. With something that moves as fast as AWS this is great.