a new iteration of HCL is being worked on currently to improve on the rough edges, it combines HCL and HIL:
https://github.com/hashicorp/hcl2
Agreed, it's a great format. I wish it would kill YAML.
I wish Hashicorp will seriously maim many of the other devops solutions. Their stuff has grew on me slowly, but I'm appreciating the hell out of their focused tools. Smells like Unix spirit.