Andrew Luck was probably the best player in the Pac-10/12 the past few years, but James was probably the most valuable. He was the lynchpin of Chip Kelly's spread attack. He gave him 20-25 carries, and he always seemed to be the center of those two/three touchdown runs that turned close games into Duck routs.
It'll be interesting to see how Oregon fares without him. There's a pretty strong correlation between how well James fares in a game and how well Oregon's offense succeeds in the field (if he hit 100 yards, the Ducks were almost certain of victory, stay underneath and it's anyone's game). Oregon now has a James-like clone in Kenjon Barner (solid runner but not quite as durable), a warp ship in De'Anthony Thomas (amazing space runner), and a power back in Tra Carson. They are deep enough at the position to endure his loss, but it will be a little bit different than before.
I must admit having plenty of respect for LaMichael, since I called pretty early that he would be the perfect running back for Oregon. He was tough, he was physical, he was fast, he was patient, and he was damned good.
However, I will not miss him finding painful ways to beat us. James ambushed us in 2009, ground it out on that final drive in 2010, then flat-out sped right past us in 2011. I'm happy that he's off to beating someone else for a change.