VON on ENUM Economics

Bob Frankston, editor at VON Magazine, publishes a solid article on one of my favourite topics -- ENUM. I love it. But, is it possible for ENUM to truly overcome the PSTN? I know that the solution is great, but will the legacy allow their entire raison d'etre just be handed over to a bunch of free wheeling communication revolutionaries? There are trillions at stake here and they're not going to go quietly. Or, are they just too slow?