[SPOILERS ahead for those not caught up on Agents of S.H.I.E.L.D..]
Agents of S.H.I.E.L.D. is going stronger than ever right now in its second season, which has only heightened anticipation for the ABC TV series' upcoming tie-in with the new Marvel Studios film, Avengers: Age of Ultron. Last year's Captain America: The Winter Soldier massively impacted the proceedings on the S.H.I.E.L.D. television show, resulting in such recurring big screen Marvel Cinematic Universe players as Maria Hill (Cobie Smulders) and Nick Fury (Samuel L. Jackson) returning to the small screen, to catch up with Coulson (Clark Gregg) and his team's various activities.
Hill shall, for certain, be popping up on S.H.I.E.L.D. again sometime in the remaining season two episodes, as Smulders confirmed during her appearance on Jimmy Kimmel Live (see above). What role she's playing in Coulson's ongoing "secret" mission (if any) and how exactly Hill's return (and possibly also Fury's) will affect the schism within the ranks of remaining S.H.I.E.L.D. agents, that remains to be seen.
The pre-Age of Ultron S.H.I.E.L.D. episode "The Dirty Half Dozen" - which is when Hill will presumably show up - will see Coulson and Gonzales (Edward James Olmos) forced to abandon their "battle for S.H.I.E.L.D.'s soul" in order to take on a new threat from Hydra - possibly, one directly related to Age of Ultron baddie Baron von Strucker (Thomas Kretschmann). However, this story thread shouldn't be another major game-changer for the S.H.I.E.L.D. TV series - not with the major Inhumans world-building and everything Coulson's been (quietly) up to recently on the show.
Popular theory is that Coulson (maybe acting on Fury's orders) is assembling a team composed of super-powered individuals - one that might not only be led by Skye (Chloe Bennet) and possibly include Mike Peterson/Deathlok (J. August Richards), but take its lead from Marvel's Secret Warriors comics with a new TV series/spinoff. It's certainly possible when Hill returns to Agents of S.H.I.E.L.D., she'll play a role not only in getting Coulson and Gonzales to unite (temporarily) against a new Hydra head, but also in getting such a secret agent team put together and organized.
Agents of S.H.I.E.L.D. may've not hit the ground running during season one - not like Daredevil has in establishing the Defenders/Netflix corner of the MCU - but it's firing on all cylinders now, with the potential to spinoff into a new ABC TV series. It's not clear yet what, exactly, the game plan is moving forward in the Marvel/ABC section of the MCU (Would the spinoff replace Agents of S.H.I.E.L.D.? Is Agent Carter going to get a second season?) - but with Marvel's Shared Universe model still rapidly evolving in a good way, the answer should be worth waiting for.
Agents of S.H.I.E.L.D. continues with "The Frenemy of My Enemy" next Tuesday, April 21st on ABC.
Source: Jimmy Kimmel Live