The CBOE is now launching Bitcoin Futures in a plan with the Gemini exchange. I am not certain what the implications are of this for the Bitcoin ETF that the Winkelvoss were working on. Launching Futures is a much easier task for the CFTC and/or SEC to wrap their heads around as the Future just has to track the Bitcoin price. Whereas with ETF the SEC has to figure out how actual trading and settlement of the Bitcoins underlying the ETF would work.
One could argue that the Bitcoin ETF would have had a much bigger impact on price that the Future. But inevitably there will be players in the market which are arbitraging Futures versus the underlying. This means more capital flowing into the cryptocurrency space. It also means more legitimacy for Bitcoin wherein regulators and stock exchanges are grasping and embracing the products.