Unfortunately it was only for the people in attendance of the D23 Conference in Anaheim, California. While we aren’t able to see the trailer quite yet, there are a few details that have been teased out.

UPDATE – YouTuber “Emergency Awesome” apparently was in the building and saw the trailer, so here’s his first-hand account of the trailer:

• The trailer opens with the Guardians of the Galaxy flying their ship, when suddenly Thor’s unconscious body slams into them.
• Spider-Man is in a very advanced looking suit. It’s possible that it’s the same one we see at the end of Homecoming
• Captain America looks like he’s been through a lot before running into the avengers again. And he’s sporting a new beard
• Thanos is wearing the Infinity Gauntlet, and already putting it into use
• Dr. Strange is seen fighting alongside the guardians of the galaxy and Iron Man against Thanos on an alien planet

There’s sure to be more to see once we lay our eyes on the trailer, but the news out of D23 seems very promising! We’ll make sure to keep you all updated as soon as more information is known.