Earth's mightiest heroes are reuniting with one of Earth's mightiest directors, as [article id="1691377"]Joss Whedon has agreed to helm "Marvel's The Avengers 2."[/article] Not only that, but Whedon's new arrangement with Marvel Studios keeps him on board through June 2015, all but guaranteeing an "Avengers" sequel by May of that year. On top of his work on that film, Whedon will also contribute creatively to the studio's other upcoming projects from the "Thor" and "Captain America" sequels to the [article id="1690976"]big-risk "Guardians of the Galaxy."[/article] He's also on tap to help develop a live-action Marvel television series, rumored to be set in the same continuity as "The Avengers."

Pretty sweet deal all in all, no? As if you need further explanation, here are five big reasons why Whedon's new Marvel gig is very, very good news for everyone.

One Universe, One Voice

Not to say that Whedon is the sole creative force operating inside the Marvel Cinematic Universe — far from it, in fact, what with Jon Favreau still working alongside Shane Black on "Iron Man 3," or the inspired directing picks in Alan Taylor for "Thor: The Dark World" and the Russo Brothers on "Captain America: The Winter Soldier," not to mention the man backing it all, Marvel chief Kevin Feige — but having Whedon on board as a Marvel Studios creative contributor certainly helps cement a unified vision for this crazy-ambitious universe. If "Avengers" is an indicator, then this is the exact man we want and need driving the Marvel movies forward.

"Winter" Is Coming

Related to that first point is Whedon's work as a script doctor. He famously stepped in to fix dialogue and tinker with the story on "Captain America: The First Avenger," and he's likely to repeat that act on "Winter Soldier" and "Guardians of the Galaxy." (With "Iron Man 3" and "Dark World" both at varying stages of production already, his influence there might not be as prominent.) With Whedon helping to bring voice to these characters he already knows so well (or maybe not so much in the case of "Guardians"), we're guaranteed to get more of those clever quips we loved so much in "Avengers."

Clash Of The Mad Titan

Calling it now: Thanos is going to walk away from "Guardians" and "Avengers 2" as one of the single greatest comic book movie villains of all time, thanks in large to Whedon. Feige previously identified Whedon as the man responsible for the Thanos Easter egg at the end of the first "Avengers," and now that the director is officially back on board to see his vision through, you know he's going to have some terrifying stuff lined up for the Mad Titan. If the death of Agent Coulson ruined your summer, just wait until 2015. Whedon's going to teach you a whole new definition of the word "brutal," a word that'll be synonymous with "Thanos" in just a few years.

Best In Show

Television is Whedon's bread and butter, and thanks to his new exclusive contract, he'll be buttering up the bread that is ABC with a live-action Marvel television show. The exact specifics are unconfirmed (though we have a few suggestions of our own for Whedon's Marvel TV series), and it's unlikely that he'll have room on his plate to serve as showrunner. But Whedon is a man with powerful pals in the TV game. Just look at Jane Espenson or Tim Minear or any other number of the highly respected creators he's worked with in the past. One or many of those folks are likely to follow him to Marvel TV, as we'll all surely see when the House of Ideas starts dominating our small screens week after week after week not long from now.

Whedonites, Assemble!

It's not just the Whedon fans and the behind-the-scenes Whedon vets that win out here, either. Think about all the actors who've worked with Joss in the past — Adam Baldwin, Summer Glau, James Marsters — who have another shot at making it into the "Avengers" sequel with cameos like Alexis Denisof and Enver Gjokaj. More excitingly and even more likely, many of these actors could well find themselves cast in lead roles on Whedon's Marvel TV series. Start writing those "Fran Kranz for S.H.I.E.L.D. Agent Topher" campaigns now, folks!

Tell us what you think of Whedon's new role at Marvel in the comments below!