I think the protocol will have to be modified. There's no way around it that I can see.

I'm thinking of something along the lines of a large upfront payment from the currency creator, and a way for them to profit from long-term usage of their currency.

Something like that would juice the fund over 100% to start (where it clearly works), and would raise the cost of a competitor entering in the way d'aniel described.

I need to think about this more first though.