The future is now
New neuroscience research confirms the old adage about the power of a handshake: people do form a better impression of those who proffer their hand in greeting (http://www.sciencedaily.com/releases/2012/10/121019141300.htm). As a human handshake can lead to better deals, so a WebSocket handshake can lead to better user experience. We investigate user experience as a combination of performance (the user is waiting less) and simplicity (the developer builds straight and quick).
So, it's up to you: do you want to build modern, truly real-time web applications? Do you want to provide your users with the maximum experience? Do you want to offer a terrific performance boost to your existing web apps? If the answer to any of these questions is yes, then it's time to realize that the WebSocket API is mature enough to offer its goodies right here right now.