I'm not sure if this exists yet, but if it does, it would totally decentralize the internet. Being blockchain powered, its content would become immutable, making it difficult for any government or nefarious organization, to take control over it and shutdown the websites living under such system.
I've heard about Maidsafe, but recently found out that it was not blockchain powered. Still, it has interesting technology that might become useful once released.
What do you think?

Internet is already decentralized
And it is conceptually decentralized. While you would have to use the DNS system to access sites using their mnemonic names (e.g. bitcointalk.org), which can be considered as some form of centralization, you can still access the same site in a completely decentralized way using its IP address. You just need to know this address, which loosely matches a wallet address in Bitcoin, as well as the IP address of your gateway. The latter can be construed as a mining node of sorts confirming your request and sending it to its own gateway or directly to the site if it is a gateway to it. Note that you don't have to pay any fees for sending and receiving network requests, and the same should be done in Bitcoin in regard to transactions