Seems trivial and more than 10 years ago.....
but water bottle plastic that is inertly neutral and doesn't make the water taste like essence of plastique. And, for that matter, energy and fluid replacement drinks and gels and such to replace defizzed coke and YooHoo....though peanut butter-and-crackers or grapes are timeless.
Greater variety of saddles including slotted.
More efficient brake pads.
lycra not wool shorts.
more chicks on bikes.
aero cable routing.
better, quieter trainers.
Better shoes and in American sizes.