I predict one of the two following things will happen:

1) Once OpenCoin releases the source for the Ripple server, we will find a way to fork the project and create a version that does not require XRP to function.

2) OpenCoin will never open source the server, making their claim of decentralization a lie.

Ripple can be a very useful system, allowing rapid payments, trading of IOUs and distributed exchanges. Its main problem is its reliance on XRP, and the company/developers that own the vast majority of them. We HAVE a wealth asset (BTC), and we don't need another one, especially not one with a central bank that controls most of it.

How could you make Ripple work without the XRP? One possibility: per-transaction proof-of-work similar to what's used in BitMessage. If not that, then something else. I have faith in the inventiveness of the developer community.