The Washington Post’s Rob Pegoraro calls SP2 a Must For XP Users:
Individual Windows users bear the same responsibility: If you run XP, you need to install SP2. Period. Loading a system update this big is never risk-free, but the far bigger risk is to keep stumbling along with an unpatched copy of Windows XP. Ask a computer-savvy friend to install it if you must. But don’t wait for the viruses and worms to stop coming. They won’t.
Generally accurate and a well-balanced view.