Hi,
We plan to write an overview doc outlining the main features and benefits of using Keycloak. This will be posted on the website and we should probably also include it in the documentation.
With regards to road map details around that can be found in JIRA, but we don't maintain a detailed long term road map as we like to be more flexible than that. If there are specific features you're after feel free to use the mailing list to ask about them. The more demand something gets the quicker we'll add it!