Yeah, it is really too bad that there wasn't even one unique drive train. I was always on the lookout for some team that did something different that just four Chiaphuas and the kit gearboxes, but could never seem to find one...
(gently removing tounge from cheek)
There were actually a number of very unique designs and innovative components this year. Because many of the "basics" were provided in the kits this year, many teams were able to focus their attention on developing new capabilities at a more detailed level than before. One side-effect of that is the new developments might not hit you in the face when you first looked at a robot, because their physical manifestations were more subtle. But I would posit that things like the noticeable increase in the use of PID controls, subtle refinements in choice of materials for wheel surfaces, gripper designs (anybody else pay attention to Team 16?), and many other advances in design were there - if you looked for them - and were significant.
-dave