Cadence is still in development and just like Flow, a community project.
We created a roadmap with the plans and ideas we have for the language here:
https://github.com/onflow/cadence/blob/master/ROADMAP.md.
Anything we forgot? Anything that you think should have a higher priority? Let us know what you think!
Also, please reach out if you want to contribute and help build any of these features!