CSS 3D in Firefox, demo
taliabale.tumblr.com
taliabale.tumblr.com
I have to say, as a web developer who is permitted to make stuff that only works in Safari, I really really love WebKit.
Yup, it would have been nice if they were on par with webkit a long time ago, but it's still an improvement and one to be excited about. One less thing that "only" webkit can do. This makes my job easier, especially when the client wants/needs cross browser support.
I wouldn't be to excited or proud about being "ABLE" to only work for Safari. You are shoe-boxing yourself, and as nice as it may be to have such a singular focus it's not so good; if at a later date you are ever forced to work outside the confines of your space.
Until webkit becomes the only rendering standard it behooves the web developer to be as versatile as possible within the web space to maximize their potential.
This shouldn't ever happen. We've been there before and seen how much it held back innovation. It is our duty both as individuals and as a collective to make sure it doesn't happen.
On the other hand, WebKit (and Safari in particular) has been very slow to add JS features Firefox has had for a while. For example, typed arrays. And the new ES6 JS bits are being prototyped in SpiderMonkey (Firefox) and V8 (Chrome), but apparently not JavaScriptCore (Safari).
Maybe Firefox cares more about JS, and Safari about CSS? Probably a huge oversimplification.
Overall though, all the major browsers seem to be doing very well these days in implementing standards. The only real holdout at this point is IE with WebGL.