[0] - https://blog.mozilla.org/blog/2017/09/26/firefox-quantum-bet...
[1] - https://en.wikipedia.org/wiki/Firefox_version_history#Firefo...
[0] - https://blog.mozilla.org/blog/2017/09/26/firefox-quantum-bet...
[1] - https://en.wikipedia.org/wiki/Firefox_version_history#Firefo...
Here's what they listed for 70.0a1 back in July, but the release notes link for today's update is a dead end.
One of the main changes for me as a Mac user is this: https://bugzilla.mozilla.org/show_bug.cgi?id=1429522#c32
Now I'd be losing the tabs/bookmarks integration with iOS's unchangeable default browser, but that's not as big a deal to me.
It has a "What's new" link next to the version number, but it links to a 404: https://www.mozilla.org/en-US/firefox/70.0beta/releasenotes
EDIT - I put in a bug report on the release notes link, response says that release notes will come out next week