XP and 2k are similar. XP is mostly a media based upgrade. It also greatly dumbs down Win2k for the computer illiterate. XP does give you more drivers on install, and more user friendly plug and play. One of the main differences is the "Luna" theme, which is what some people call the "Candyland" theme. This can be disabled though.
Pretty much all of the changes in XP are aimed at home users who are computer illiterate, so thats why businesses who are already on Win2k don't see the need in upgrading to XP. Now that MS has ended support, they are going to have to.