I'm just throwin' some ideas out there to chew on, so here's something else...

We already have this concept of a node in the P2P network, which is essentially a machine running the Bitcoin client. And that Bitcoin client has a certain role in all this, which is well established. Maybe we need to introduce some sort of new concept. Perhaps a collection of nodes could act as exchanges.

Part of the problem, with regards to scalability, is staying within the limits of the $1,000/$10,000 trading rule.

One way to work within that limit is to make it easier to build exchanges, such as I suggested with some sort of OS framework that could be easily implemented, both quickly and cheaply.

Or, perhaps we need to add some new concept to the P2P network, where the work of the MtGox type exchanges could be off-loaded to some sort of anonymous, decentralized network. I'm sort of weak on implementation ideas on that option though.