Apple has just released desktop Safari for Mac and Windows to 4.0.4, which improves full history search performance, has the mandatory stability improvements, and security fixes, but the big news as far as we’re concerned is the number one item on the list — Improved JavaScript performance

Desktop Safari is the big brother of the iPhone’s Mobile OS X Safari, and they share a rendering engine (WebKit), and a JavaScript engine (Nitro), and improvements in desktop Safari and Nitro have traditionally filtered down to Mobile Safari with the subsequent iPhone OS update. That’s right, we’re looking at you iPhone 3.2 (where ever you are!)

Since the current iPhone 3.1 Safari is still outperforming even brand-new devices like the Droid, that may seem a little greedy, but we know Google’s Android and Palm’s webOS aren’t sitting still in the rendering race, and have updates of their own in the pipeline, so once again, competition benefits the end users. Bring. It..