Update Upcoming Features page

[aarongable]

• Remove very old already-launched features
• List more upcoming features, like maybe ARI
• Update phrasing on existing items to provide more detail where appropriate

[bdaehlie]

I pushed some updates directly. I left some of the most important older items. If my push resolve this issue entirely go ahead and close, otherwise propose a PR? Thanks for pointing out that we need to do this!