I understand your rant, especially in regards to how Vista's performance is probably hindered by all the flashiness. But I think there is something to be said in regards to having a zen-like desktop environment. I understand why the Mac interface appeals to people, and its not all about just being hip and trendy. I plan on buying a Macbook fairly soon to complement my Windows machine. One I'll use for gaming and general internet use (PC), the other will be for music and video editing (Mac). I think there's a certain subconcsious state I like to be in when I work on my creative projects, and I just like the was Mac OS works and looks. It feels very modern, clean, and sterile. I don't get that feeling with Windows.
And really, you can't expect Microsoft to stick with an old-looking interface and risk losing more marketshare to Apple. The mainstream populace cares more about what's popular, not necessarily what's more functional or practical. How else could a business sell a plain white t-shirt with a Tommy Hilfiger logo for $50.00? Or an iPod for several hundred dollars for that matter? (someone literally just mentioned an iPod nano in my office after I typed this.) Eventually Apple is going to catch up with Microsoft once they've convinced enough people. If MS doesn't have the right look by then, they're going to get passed up, whether the OS is better or not.