^ Yup, anything beyond the 6 officially confirmed is just speculation at this point. I'd bet good money on Spider-Man being playable, but beyond that, I don't know. Fury is a possibility - we see him riding a motorbike, but don't know for sure if that's a cutscene or gameplay footage. Wolverine is a possibility based purely on how popular he is and how well he'd sell, but it obviously depends on whether they want to bring X-Men into the game. I'd say the same for Loki - the movies have made him incredibly popular, so if we're getting any villains, I'd imagine he's top of the list.
Somebody's probably already mentioned this, but during the template footage, when the screen shows the orbs being repositioned, the righthand side of the menu has villager figures. The first one, to my eye, looks like Elinor from Brave, so she may be unlocked through Merida (I'd love to see a figure of her, but I don't know how likely that is). The second could be a Angelina Jolie Maleficent (as opposed to the classic Maleficent from DI1) or maybe even a bear from Brave, it's tricky to tell. Beyond that, I can't figure the others out, but I'm sure people with better eyesight than me have already identified them.
![Wink ;)](./images/smilies/icon_e_wink.gif)