I just got an email inviting me to partake in the beta for a game called Marvel Heroes. A quick internet search turns up that this is an free to play action RPG (ala Diablo) using characters from the Marvel universe. So instead of being a wizard or a barbarian you can be Wolverine. It sounds like it'll use the League of Legends model where you pay money to unlock more characters, which is nice compared to a pay to win model.
That said, I don't want to play betas, and I've never really been a big comic fan so I don't feel terribly inclined to play the game. The beta key in the email doesn't seem to be linked to my email address or anything, so if anyone is actually interested in giving the game a try and wants a beta key, let me know and I'll forward you the email. First come, first served!