Marvel playable villains confirmed as Green Goblin, Loki and Ronan.
John Vignocchi: Yes, our announcement of Guardians rounds out the entire first wave of the Marvel Super Heroes available at launch, but the first three characters of wave two are Loki, Green Goblin, and Ronan. There will also be more characters—besides the villains—added as well, but those are the first round of characters from wave two.
UPDATE 2: Villains trailer added below (Thanks InfinityFan for the find)
hopefully a better picture of the figures will be available soon. but for now ...
UPDATE: image courtesy of Stitch Kingdom ...
Links to Ronan's, Green Goblin's and Loki's pages:
Ronan
Green Goblin
Loki