Jack-oh;
Actually with the advent of ADS-B or whatever comes after that <G>, there won't be a need for the old transponder as we know it in the future. The ADS-B will have it's own unique identifier which will tell you the aircraft identification as well as the type of aircraft...
regards
Scott
PS. It is just going to take a long while to mandate equippage so that everyone can use the newer systems. Costs money and that is hard to get mandated.