I think given the trend towards more and more technology we are going to see this type of system more and more in bikes as well as cars and even more.
Like it or not, I think we are headed towards the day when we have the "One fob to rule them all" That is one transponder we carry that would start our car, our bikes, allow us to pay for groceries, unlock our homes etc...... There are a lot of security concerns with that but in time it could be worked out...