Is Nintendo using the exact same sensor bar? I could not find anything on it, but it really needs an improvement.
It has to use infrared that much we know, but it needs some improvements if any could be made.
Look at issues the first sensor bar had. It was prone to interference from any heat source specifically the sun. So the expectation would be for Nintendo to make a sensor bar that combats this flaw. The sensor bar did not work being a reasonable distance away from your television. So increase the range.
This is not a flaw Nintendo should take lightly. The sensor bar was and could still be a major barrier to entry. Anytime a consumer has to rearrange the room for the product they bought is bad for Nintendo. Nintendo is trying to and will always try to make synonymous intuitive products and the sensor bar is in direct contradiction with this. How many Wii owners thought the controllers were not working well when really the problem was that the sun was shining into the room. I have had to help many people with this problem and the frequency of their gaming time went up.