Windows 7 is nice. I was pleasantly surprised at how better than Vista it is. But it still does nothing for me that XP doesn’t and even though Win 7 is on my system I’ll continue to primarily use the faster and locked down XP until it’s no longer supported. I expect millions of businesses will do the same.
For a little while perhaps, but MANY of those XP machines are going to become effectively obsolete in a few more years. Clearly, when upgrading machines, you'll want to select a OS that is fully supported. IOW, while the "death" of XP may be a bit premature today, it still is eventually unavoidable, just like 3.1.
FTR, I have 7 installed on all of our home machines, our family business machines, as well as the 28 machines at a not-for-profit I help to run. I don't have a single complaint. The transition was effortless.