Predictions for todays event

Anyone have predictions on what to expect from todays event? I know they promised big announcements, but we all know there is a big range with that statement.

Personally, I still am wondering why D23 this year is being held as such a large space. Could they be planning on teasing something today to then follow up with details in August?

Over/under I put it as more details of villains land and a time table possibly.