Walker-I think he'll make a great leap forward with a real offseason, and with Dunlap at the helm.
Gordon-Three point range that's crucial down the stretch when you're behind.
MKG-He needs to be on the floor as much as possible. Athleticism, defense, rebounding, and ability to get to the hoop and the line.
Mullens-Range, and I think he'll show some improved defense. He also stretches the floor better than anyone on the team, allowing us to unclog the lane a bit.
Biyombo-I might actually go Haywood here. Just for the size, and ability to protect the rim. Either way, I'm looking for my center to do little else than protect the hoop, and grab rebounds. Both are capable.
Edited to add reasoning.