I really think Dan is going to be forced to cap nodes at a certain number just like Bitshares and Darkcoin before this is out the door. For monetary incentives and security-wise.
Why? - like BTC, work is rewarded. The more transactions, the more profitable it is to run a client. If its not profittable, people will shut theirs down and the revenue for the remaining nodes are increased accordingly. Its will be self regulating by the incentives already put on the table
You do not need some centralized shit to regulate incentives. People will figure out themselves if it makes sense to donate ressources or not.