Windows XP - The eXPerience Thus Far?

An Anonymous Coward asks: "So Windows XP has been out long enough for those of us in the IT field to have our managers, users, and vendors hitting us up for it (Redmond's marketing apparently worked). So, how has Windows XP affected your IT department and company thus far? Are you using it, or planning on using it? What made you decide to migrate? What problems have you run into, and what features have you found beneficial? Please leave out the anti-MS/pro-Linux rhetoric unless it is directly related to an issue you have with XP. Thanks!"