The idea has a huge amount of merit, not necessarily for Bitcoins.

Suppose I start a company and decide to issue its shares as a block chain.  Instead of miners getting 50 shares each, the block chain would be programmed where I just issue all the shares up front to the proper shareholders, etc.  The block chain is used as a means to buy and sell the shares on the peer-to-peer stock market (which doesn't exist yet).  Miners maybe get transaction fees.

In such a case, proof-of-stake voting might be fantastic.

But I don't see what relevance it would have to Bitcoins as they are now known.