Because I use a Mac at home, and the Vista decision at work is out of my hands. But from what I hear about Vista, I'm in no hurry to be upgraded at work. Vista offers very little that XP doesn't already provide, and it comes with a huge performance hit.
"Show me just what Mohammed brought that was new, and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached." - Manuel II Palelologus