[kawsper]

They announced it a couple of days ago: http://blog.dota2.com/2018/08/the-main-event-with-new-steam-...

It still have limitations and bugs, yesterday it just wouldn't load for me, but it works now, and you are unable to watch yesterdays content.

[ehsankia]

The UI is very wonky, definitely looks like it was rushed last minute to release for TI. That "Watch with friends" button is pretty messed up if you're logged in. Also if you're logged in and "close" the stream tab, I don't see any way to get back to it. Definitely a work in progress.