Colored Coins can be used to issue stock with dividends and bearer bonds. I think it's a mistake for O to use counterparty unless they clone it. Even then, there is too much reliance on the blockchain as data storage. A Blockchain.info style online Overstock Colored Coin wallet would be a better way to go for issuing stock. You would have the ease of access of an online wallet, the security of an encrypted wallet, and no risk of accidentally recoloring coins. There would be virtually no costs (just a satoshi) to issuing a share. It currently costs .5 xcp (about $1.50) per share to issue a stock and this will probably rise.
There are regulations regarding the reporting of holders of stocks as well as the reporting of who is behind both orders and executed trades of stocks (this is to monitor and prevent insider trading and to prosecute insider trading when it occurs). Colored coins would prevent any of this reporting from happening.