Beast and Electra are both going to be 200 ES heroes released next year, IIRC. Do we have any other, non-AP2, confirmed heroes in the pipeline?
With the way the devs talk about stuff, we know a lot about their pitched ideas and what they're trying to do, but like with Elektra, we don't have super solid confirmation outside of their word for a lot of stuff, and anything could happen.
By my memory:
Agent Venom- Mentioned that they are doing him "guaranteed", not a Venom enhanced.
Archangel- In talks with Marvel about future plans, implying his release will be tied to an event. Was a "safe bet" for 2015, but because of this is now delayed.
Black Bolt and Lockjaw- on the short list, almost made the cut for 2015.
Captain Britain- Coming "eventually"
Crystal- In the works using Doom's tech.
Dazzler- Mentioned as coming in 2016.
Domino- Confirmed as someone they're committed to doing, but "not a good fit" for the pack.
Electro for some stupid reason.
Falcon-They don't want an Uncle Sam costume for Cap because they're planning playable Falcon.
Gamora- "Will be playable" but not in 2015.
Gladiator- High contender for the 2016 advance pack
Havok- Likely part of 2016 advance pack.
Hercules- Almost made this advance pack, still high on the list.
Howard the Duck- Will be playable eventually, team-up in the pipe fist.
Jubilee- Will be playable "Eventually", already having her powers planned out.
Magik- Coming 2016, most likely as a 200 ES release.
MODOK- Almost made the 2015 pack, still on the short list.
Mystique- Almost made this advance pack, still high on the list.
Nick Fury- More or less confirmed coming either 2015 or 2016.
Polaris- Will be "playable eventually"
Red Hulk- Mentioned previously he and Agent Venom are in the same boat, Flash has since gotten much more solid confirmation several times over.
Sentry- Intended playable, but "not any time soon".
Spider-Woman- Likely for next year.
Super Skrull- They confirmed two things; he will be at least 400 splinters due to the workload despite using other characters powers, and he still isn't ruled out as 2015 surprise release.
Thanos- Will be playable, like Doom, but only when the story gets to a certain point, probably not for another few years.
Others:
Agent Coulson- Eventually, likely to have Maria Hill enhanced alt.
Ares- Might be in the game "eventually"
Kaine Parker- "If we do Kaine, it'll be as his own hero" was the most recent response.
Multiple Man- "Has a chance to be playable some day"
Quicksilver- Team-Up likely, doesn't seem feasible with current internet connections, maybe some day.
Namor- They now have the ability to use him, but this only changed /very/ recently, so no current plans.
Nextwave- Not any time soon, but eventually possible.
Runaways- Possible in the longterm for playable heroes.
Songbird- Same as Multiple Man.
Young Avengers- Possible in the longterm for playable heroes.
Warpath- Planned playable, but not on "the short list"