enjay, XP will work for a long long time yet, for as long as you want it to in fact.
What will happen is that there will be a phase-out of support for security and virus programmes.

All you have to do to keep it safe is not to visit questionable websites. Downloading your usual data and betting on the TAB or bookies sites should be safe. They have a lot more to lose if they allow viruses to infect their sites.

I use the latest and fastest computers, but that's just me, I need it and I like to upgrade, but if it works for you and does the job you want it to do, I can't for the life of me see any reason for you to upgrade.