I think they make obvious that hardware doesnt matter
It matters most of people staying with windows XP is because
1. Their computer cant upgrade to Windows VIsta since the beginning (obliviously Microsoft intentionally forgot about Vista) as the processor /Memory doesn't deserve it.
2. XP is stable enough to run MS office, read emails and browse internet (most usual office's tasks)
3. Microsoft obviously doesn't care you have to spend a ton of money in RAM memory (if your motherboard allows it) and of course a faster processor with an upgraded video card.. it is the bottom line get more money out of you!