Would it be possible to shift the entire mining process to a system similar to p2pool that would include a signature based on it's own tree?  Then just accept blocks that are also signed by THE decentralized mining pool so everyone has to use it.  I guess it's a "one true way" approach.

I'm loosely thinking about something like what p2pmining.com is attempting to do.  Perhaps existing pools would submit blocks through the main p2p pool where they would be signed, maybe paying a small fee that is distributed to miners in the process.  Basically all miners/the masses would work together in a single p2p mining pool as gatekeepers to the actual blockchain.  External pools could still exist but would need to still submit blocks through the main p2p mining pool and pay a small fee of each blockreward to be signed and accepted.  I know there would be a lot of complexities to work out, I'm just thinking out loud and wondering if it would even be possible and what the potential problems would be.