I still wonder if Marvel will try to keep Fox from using the Marvel branding on the film if they can, to stop Fox from trying to cash in on the good brand image Marvel have built up with cinema goers. Perhaps Marvel could say that they are doing it as they are worried that the film could damage the Marvel brand. And it wouldn't be the first time that a Marvel based property was advertised without the Marvel logo, Big Hero 6 is not using the Marvel branding (although not due to worries about the film damaging the brand.)
It might sound far fetched, but if Disney are willing to kill the F4 comics just to screw with this film you have to wonder what else they might do.