Idea: Have a dedicated platform status page for Firefox, similar to https://chromestatus.com/ or https://webkit.org/status/
Reasoning: The Chrome Platform Status website is a useful tool for finding what web standards are supported or going to be added in Chromium/Chrome and also lists the upcoming releases and what additions or removals will be in said release. Having a convenient list of what standards Firefox supports or is going to support can prove to be a useful resource for any web developer.