This is awesome, I would definitely use this. Even just 4fun.
Even more it could be anonymous and independent. I suggest using a blockchain merged into bitcoin like namecoin is planning to do right from the start, so there would be no disadvantage mining in it (as for lost opportunity for bitcoins).
There could be lots of services employed in this matter, from usenet to ip (tor replacement srsly it sucks) over filesharing and even ospf routing for community networks.
This could become big... I all depends on the development of bitcoin popularity and the acceptance for such secondary currencies with a specific use and the general adaption within the community.
PS: Is is right that the idea is about "A decentralized email system in the spirit of namecoin?"