Security updates for XP - they're the ones XP users won't be able to get anymore when they re-install it, (maybe not even the old security updates but don't quote me on that)
Should be fine as long you install a trusted AV & Firewall package (and keep it updated). I've always disabled automatic updates anyway, on Windows XP, Vista & Win7. I hate it, a damn nuisance and a regular source of grief. I have always installed a trusted & reliable third-party firewall + AV, never used IE and I've been fine.