There is security intelligence that indicates that there will be malicious attacks on XP. These are zero day threats and anti-virus and malware companies are unable to block the attacks, until after the attack has occurred and a counter-measure has been created.
Microsoft will not provide any security updates unless a business pays for Custom Support. You must have Premier or Enterprise agreement in place with Microsoft. Custom Support cost $50 per machine per quarter and you need to purchase Custom Support for a minimum of 750 machines. At least that's the deal I got from MS. I think I saw an email from MS that they changed the terms earlier this past week, but it did not change our agreement since it was already in place.
Even with MS Custom support, XP boxes are not protected until after a threat has been discovered. Additional security measures should be in place and there should be no PII or IP information on those boxes.
For what is worth, part of my job for over the last 15 months has been migrating 80,000+ XP machines to Win 7. When I left the office yesterday, we had ~260 machines going on Custom Support and another 200 or so machines segmented from the network.
BTW, I am personally OS agnostic. At home, I have Mac OS, Win 7, Linux, iOS and Android OS. This post was written on an iPad, running iOS 7.1
In general isn't that the way it's been always?
Would running Win8.1 and using Office 2003 be safe?