here is my thoughts as someone that worked with mobile operators for long time:

1. reading site and faq i see mostly topic about tokes, its distribution etc etc
2. white paper give very brief technical details how they suppose overcome all obstacles and the list isn't just big... it's HUGE
  a. in order to provide the best coverage for best prices u need (according to your technical details) perform integration with every one of telco u want to work with (i.e. support it's service for interchange). regular user cannot just send it's data bandwidth to someone else and tight integration with telco is needed. have u ever integrated with telco? well... i assume not. since this is THE MAIN CONCERN. telcos are not just paranoid on security, they are total crazy... and providing u "entrance" for getting into holy grail of their premises... well... good luck!

3. let's think on behalf of telco: what intension it has to give it's data that his customer already bought to someone else? for this particular telco it's LOSS! since instead of selling to new customer full package (let's say 2GB for decent price), this customer gets some data from other customer and telco gets NO PROFIT.

and in order to get this "NO PROFIT", telco also need to provide u with the interfaces for connectivity, work with u and support your api etc etc. what i see from telco perspective is NO GAIN. do u think telco thinks about how spare some bucks for its customer? i assume not... they think how to sell u more and earns more money...

if this solution is gonna work only with support of law enforcement why your technology will get mature, but from my experience it shall take 3-5 years. none telco will give u hand till then.

imho, this is totally incorrect bringing basically anarchic scheme to such conservative and greedy world as mobile! the approach shall be different...