The Heisman has less meaning than a Nickelodean kid's choice award. It is a popularity contest voted on largely by people who won it before, and the media.
Think of any award or position where the gatekeeper is a combination of previous winners and the media. If there is another one I bet you'd either find it is totally corrupt or meaningless.
Supposedly the media gets to vote because they are "informed and objective." The unwritten meaning there seems to attempt to balance out the votes of past winners who are likely neither. The statement about the media makes no sense, on its face, as the media polls were actually booted from the BCS calculations because they were neither informed nor objective.
Personally I believe a step up for the Heisman would be to vote on the winner American Idle style. Or Survivor style.
Or, the Heisman could simply add meaning by making an objective set of criteria (ex: must be a junior so there is a body of work to review), and having a truly objective panel weigh all criterion and vote. If a player doesn't get a certain % of the vote, the award isn't given. Also, it should be voted on after bowl season so every game can be accounted for.