Cross-play looks awesome. Glad they implemented it.

What does stream to all windows devices mean?

Lots of good stuff in this conference. Very happy with it
Just sad we didn't get a new X1 OS shown

Streaming to Windows!! So excited for that :D

Think psvita playing ps4 games, is the same. 

You need XBO to do it, so that's fine by me.

So we can't play PC games on Xbox One but play Xbox games on other devices? How would that even work? I'm wrong aren't I?

I believe you can stream the games from the Xbox to another Windows 10 device and play it there (so it's still playing through the XOne, kinda like the Wii U with the GamePad). Though I don't think it works the other way, no. 

So can someone tell me everything that happened that's important?

I said the series.  

Stream as in play on a Windows phone? How? How can i play Killer instinct on a tablet? Or Phone? Replying kinda late