So Squadron Supreme was depicted as villains for most of Avengers Assemble season 2. I've been thinking, and this is just me, but given their villainous behavior and actions, I don't think that the team the Avengers fought in those episodes were Squadron Supreme at all. I believe they were really Squadron Sinister. Looking at the concept's comics history, it could make sense, and the show's writers are probably saving that lil' revelation for a later season. What do you think?

@darkmount1: Yes they would make a great returning villain team. They could also add some more members staying with the original Sinister team theme.