I completely understand your situation but let me help you.
Please be aware that the XP Operating System has been in the market for the last 12 years now and the support of it is ending. The graphics controller you just got is one of the latest ones from Intel® and it has been designed for newer Operating Systems.
You can check the Graphics controller support here:
Here you will find some information from Microsoft about XP Operating System.
I don't think that support ending justify the lack of drivers, there are a lot of situations (ie: dualboot, old software or using a known solid OS) where OS migration is NOT desirable, but new hardware is, so intel as a manufacturer should provide drivers for it's hardware. There are millions of happy XP users which are forced to migrate and reinstall everything, sometimes loosing support for other old but useful hardware like scanners, or specialized I/O cards. People will end up with windows 7 not because they choose but because you force them to do that, and might migrate to AMD (which supports XP and their philosophy is less pushy). It's not hard for Intel to release XP drivers for their hardware and it will help to avoid angry customers like us.
Same with USB3 drivers, 3rd party chips (ASMEDIA) do work with XP, intel doesn't...