As usual, the cynic steps in!
I am more of a loyalist towards Microsoft than most, and I get on well with all their products. But it surprises me that it took a team of, I believe, more than 20 personnel to come up with the final desktop. With a couple of hours discussion of the basic requirements, I think the average graphics enthusiast could have produced that final version in about 15 minutes.
However, on the subject of the though behind it. I can understand the need for something with very little graphic intrusion, but it seems that, when looking through threads where members show off their desktops, a majority , almost on their first customisation, seem to change the standard for a graphically heavy picture. Perhaps the Microsoft desktop designers should have just introduced an unadorned, simple, one colour desktop, with the options, still there, to change to whatever they fancied?