ORIGINAL: vertical grimmace
Not sure if it is true (my local hobby store is very often wrong) but the Local Hobby clown has told me that Futaba is discontinuing it's 72 mhz equipment. No one has said when though.
I think the hobby shops and distributors, not the manufacturers or the FCC, will be the ones who "kill" 72 mhz in the US. One LHS told me they will not be reordering any 72 mhz equipment. So, when they run out, 2.4 will be the only thing available in the store. If the majority of shops plan to do the same thing, the distributors will stop importing the 72 mhz stuff. Even if it continues to be manufactured, and sold in other countries, it may be hard (or expensive) for us to get it.
It's easy to say that there is "no market" for 72, but the distributors and stores can control the market to a certain extent by only handling what they want to sell.