With the title "A Long Awaited Return...", the teaser features a golden cross on a black background; the cross echoes the (generally red) symbol on the Nova Corps' helmet, much like the one Sam Alexander wears in "All-New, All-Different Avengers."
The teaser also references "Avengers: Standoff," which concludes in next Wednesday's "Avengers Standoff: Assault on Pleasant Hill Omega" #1, so it seems we'll soon learn who will be making a big return.
Several Nova Corps members are currently unaccounted for, including fan-favorite Richard Rider. Additionally, the solicitation text for Mark Waid and Mahmud Asrar's "All-New, All-Different Avengers" #10 teases "The Search for Nova's father," which implies the Avengers will get word that Jesse Alexander is alive.
Of course, the teaser could have nothing to do with the Nova Corps; the image could just as well tease the return of Quasar, the original Captain Marvel, Darkhawk or someone else entirely.
"Avengers: Standoff" draws to a close in "Avengers Standoff: Assault on Pleasant Hill Omega" #1, which goes on sale April 27.