well, i for one would assume their style would adjust to the character. their style is different because it needed to be different, and because when marvel started up dc's style was getting old and wasn't as successful as it had been. marvel doesn't have experience with anyone LIKE superman. all their major players appeared almost as a unit or within a few years of each other.
now styles are much closer. i don't think it would be much of a stretch for them to accommodate superman and treat him in a way similar to the way dc does. readers would still be readers, and they would have expectations. it's the readers as much as the company that dictates the way the characters are treated. /shrug
marvel does seem to have less interest lately though in maintaining 'tradition'. that's why i said i think their treatment of him would change over time, but i'd be surprised if they did anything permanent to seriously alter what he is now.