I interpret it as the player who has had the best season, which I see as a combination of statistics, highlights (game-changing moments), and team success.
Here is how I would vote (not how I see it turning out in NYC unfortunately):
1- Mark Ingram, Jr., Sophomore, RB, Alabama

First off, it's a damn shame he didn't stay in Big Ten country. He grew up in Flint, Michigan and his father played at Michigan State before going on to the NFL.
Mark Ingram is currently 5th in yards, but also has a 6.6 ypc, which is better than four of the five people ahead of him. His 246-yard performance against South Carolina put him in the running, and his 144-yard performance in a crucial game against LSU reaffirmed his position as the top candidate thus far.
His Alabama team has one of the best defenses in the country, and coupled with Ingram's play, is arguably the best overall team in the country. They are 9-0 and on their way to face Florida in the SEC Championship game. Assuming Alabama finishes 13-0 prior to the bowl game, Alabama will have its first Heisman winner.
2- Jimmy Clausen, Junior, QB, Notre Dame

I'm a Notre Dame fan, I admit it. I'm not the largest homer in the world though. Ingram has a huge lead tight now, everyone else is basically battling for a spot in New York.
That said, Jimmy Clausen is best quarterback in the country. Juxtaposed with everyone in the country, his QB rating is 3rd (162.9), his yards are 4th (2,770), his touchdowns are 8th (20), his yards per attempt is 7th, and his completion percentage is 9th. Also, among the top ten touchdown leaders, he has the fewest interceptions. You will find quarterbacks with better team success, but go ahead and find a quarterback with statistical accomplishments like those (that don't result from a system).
His defense, or lack thereof, doesn't facilitate winning. In fact, Clausen has had to put his team on his back (with the help of Golden Tate) to win games.
3- Colt McCoy, Senior, QB, Texas

McCoy is coming on later, partially due to his name, but mostly because Texas is starting to click on all cylinders. His 470-yard performance last week (against Central Florida...) reminded us all of his season last year. He is statistically the most accurate passer in the country, but his interceptions are not impressive at all.
He also has team success working for him. Texas will be in the BCS National Championship game if they win out. Not many other players are leading their teams to such heights.
4- Golden Tate, Junior, WR, Notre Dame

Oh Jesus! The Notre Dame fan has lost his mind!
No seriously, name a more exciting receiver. His stats speak for themselves, he is 3rd in both yards (1,059) and touchdowns (10). Among the top ten yard-earners, he is 2nd in average (16.6ypc) and second-lowest in terms of catches with just a mere 65.
He's a stud and his highlights speak for themselves. What he did while Michael Floyd was injured (and teams were double and triple covering him) is nothing short of remarkable.
Still though, this Heisman belongs to Mark Ingram. As long as it's not Tim Tebow, I'm happy.