Some substantial spoilers in the attached, obviously. Mostly highlights of things that didn't happen in AAoU based on a lengthy Joss Whedon interview. (There's more on the bits about Thor here: http://www.geeksofdoom.com/2015/05/05/joss-whedon-thor-avengers-age-of-ultron-subplot .)
That there were 54 minutes eliminated from the rough cut makes me really hopeful that some of this stuff shows up elsewhere.
See Alternate Avengers: Age of Ultron Scenes — Vulture
Joss Whedon went into Über-specific detail.