Capcom's Seth Killian was asked about if fan feedback ever makes its way into their games, he had this to say on the subject from the Unity Boards.
Does Capcom accept fan submissions? I was just wondering.
Seth: We do actually use your ideas. The thing we CAN'T take is your ideas for a whole game -- no matter how many contracts you sign agreeing not to sue us from space with lasers, apparently this is still a legal minefield that no publisher is willing to walk into.
But yes, as was pointed out, we actually do change existing or in-development games based on fan feedback all the time.
You might say that's even why we're here.
A prime example of this was Street Fighter 4's roster. A poll was held asking players who they wanted to see (at the time) in the upcoming game, and the top 4, as voted by the fans, were included in the title.
