The new Fuel is a slightly higher aspect ratio than the 2002 kite. Slingshot was the first to come out with a "moderate" aspect ratio high performance kite. By increasing it slightly and adding the scalloped ends, they are increasing the tuning and upwind performance of the kite.
Durability also looks better than the 2002 kites. Boards are a bit lighter and the graphics are better (except for the Jarvis - I like the old graphic better).