I know we don't need another Vista thread, but AnandTech have done a preview of it here - http://www.anandtech.com/systems/showdoc.aspx?i=2780 They spent a lot of time comparing it (mostly unfavorably) with Tiger. Some lowlights: It takes up 10GB on the hard drive (although debugging is enabled so that takes up a lot of space). It very quickly eats up RAM (again when debugging is off, that is likely to be reduced) The Expose clone is badly done (harder to use, artifacts in the angled view making it hard to read the contents of the windows). The new security model is a real pain. Games performance is much lower than XP. General performance is lower but not as bad as for games. Vista Basic uses 97% of the CPU just to move a window about on the screen: see http://www.anandtech.com/systems/showdoc.aspx?i=2780&p=13 In all my years of using Windows, I never realised that moving a window around the screen requires 30+% of the CPU. I just compared to OS X and it's true - I see CPU usage spiking at 30-40% in XP. OS X is barely above 10%.