Induction stoves/stovetops. They are not compatible with all cookware, but I'd like to see a face-off with gas cooktops for speed and efficiency. Maybe a collaboration with America's Test Kitchens would be in order here.

I believe those portable counter top units used on the cooking segments of the Today Show are induction because they seem to be amazingly fast, but I have never seen a portable induction stovetop on the market.

They are expensive, but maybe if they compare well to a gas stovetop, then demand would go up and prices would come down.