At present you can buy an OEM version of XP with any of a number of qualifying items of hardware. eg hard drive, processor, memory, motherboard, even keyboard, mouse or IDE cable. As long as the computer needs it to run it qualifies. There is nothing to stop any home builder obtaining an OEM version of XP with any of these components.
The only restriction is that the computer cannot be sold on.
Did the article you read give any indication that this practice was being discontinued?