I've seen this heaps now. Everyone wants a transparent, glossy black interface for Leopard. But why? Is it because Vista has it and therefore it is the new flavour of the month? Seems to be that way. Everyone keeps point to HUD palettes, Quicklook, Coverflow, AppleTV and the iPhone. So what! They are all specific interfaces for specific needs. HUD palettes are designed for media where you need to select options but not have it distract your view of the media behind the palette. Quicklook is just a HUD palette. Coverflow is there to make things look good. Black shows off images really well and album art are just images that Apple want to show off really nicely. The scrollbar and buttons are black so they don't get in the way and are glossy so they are noticeable enough. AppleTV again is dealing with media so needs a darker interface. Also black will stop image burn in on plasma displays. The iPhone interface has many different parts to it though. Transparent black to show off the wallpaper, black to match in with coverflow etc. Apply transparent, glossy black system wide and you end up with nothing more than visual noise.