The new Safari does look nice at initial glance. What worries me about it is WebGL is not enabled by default, and its JS engine is much slower than Chrome's. I mostly do WebGL game dev for my personal projects, and so I don't support Safari (since I can't expect people to have turned WebGL on).
It isn't? That's strange. Why would they do that, security reasons?
About JS performance: Might be important to you as a gamedev, but for the overwhelming majority of today's web apps this shouldn't be an issue anymore.
That being said, I will probably still switch back to chrome when they get retina support. The interface is just cleaner and it has more intuitive developer tools IMO (safari's are more powerful, but chrome's do have everything I need and are easier to navigate).
