
It seems there are some easter eggs in the recent Thor: Ragnarok trailer that hints at more classic Marvel Comic vets entering the cinematic universe.

Hinted in the very first scene here, we see the central tower bearing the bust-likenesses of a few Marvel characters that are connected to the Thor comics. Namely Man-Thing (front and centre), Beta Ray Bill (below and to the left), Ares (straight across to the right) and Bi-Beast (directly below Ares).
Man-Thing is Dr Ted Sallis, who was transformed into a magical, empathetic swamp creature (not to be confused with DC’s Swamp Thing).
Beta Ray Bill is a horse-like alien and ally of Thor who was worthy enough to lift Mjolnir. He was later given his own hammer and has a longstanding connection to Asgard.
Ares is Marvel’s equivalent of the ancient Greek god of war, more recently reimagined as an anti-hero type. No, not that Ares.
Bi-Beast is a two-faced android linked to the Inhumans, who has fought various heroes including Hulk and Thor.

Thor: Ragnarok is scheduled for release on July 28th 2017