[Warning! Avengers SPOILERS Follow!]
Marvel Studios is still riding high following the gargantuan success of The Avengers, which delivered two-plus hours of enjoyable and exciting superhero cinema. (Warning: Avengers spoilers ahead!) While the real takeaway from the film was seeing the assembled team of heroes working together, fans were also given a very intriguing mid-credits button scene that introduced the villain Thanos to the cinematic universe, ensuring everyone that there is still plenty to be excited about for Marvel as it enters "Phase II" of its film endeavors.
Also seen in that mid-credits scene with Thanos was his henchman - known simply as "The Other" - who appeared multiple times in the film, working with Loki and eventually providing him the Chitauri that invaded Earth in the final act. "The Other" is played by actor/frequent Joss Whedon collaborator Alexis Denisof (Buffy the Vampire Slayer, Angel, Dollhouse) who is completely unrecognizable in the movie, both in appearance and voice. Denisof spoke recently about his involvement in The Avengers and whether he'll have a role in future Marvel films.
Denisof joked about the "gag order" put in place once he secured the part, and while he might have missed out on all of the hype surrounding the film up until its release, fans (along with writer/director Joss Whedon) have to be pleased he didn't risk spoiling anything; Thanos' cameo did in fact drop like a "secret bomb" the way Whedon wanted it to, and elicited the desired response from devoted Marvel fans.
If you want to hear Denisof talk about 'The Other experience' in full, head over to IGN.
It's certainly not a stretch to imagine Marvel bringing Denisof back as "The Other" in whichever film(s) where Thanos serves as the main antagonist (Guardians of the Galaxy? The Avengers 2?). Big villains typically have some sort of underling by their side, but Denisof's involvement wouldn't make or break an upcoming movie, by any means. Given the number of characters Marvel will already be working with in its future films, the likelihood of "The Other" serving as anything larger than a bit player is pretty slim. If "The Other" is seen in more movies, he'll most likely be in a role very similar to what we saw in The Avengers.
Denisof probably isn't involved in too many of the meetings where Marvel films are hashed out, but he does acknowledge that there are "very cool conversations" taking place as to what's next for The Avengers follow-up. That Denisof has even that much insight suggests he could be popping up as "The Other" sooner before later.
We will, of course, keep you posted on any and all news related to future Marvel films - including any word of inclusion for "The Other."