Talk about excitement. Microsoft has got a new game going on its website: Guess the Launch Date of Windows Vista. We can hardly contain ourselves.

If you take a guess, you get served a video which … wait for it! … hints at the true date.

Hold on. What makes you think they know the true date themselves? Hasn’t the Vista release been a moveable feast since … well, Biblical times (in technology terms)?

Ah, well, some bright spark has worked out the hint and come up with … December 1.

“By simple iteration I quickly found that ‘early’ ends Nov 30th while ‘late; starts Dec 1st. So either one of these will be the launch date. If this all is not a dirty little trick from the webmaster, of course…”

What are we to make of that?

First, it needs to be in the shops by very early December.

Second, the OEMs (own equipment manufacturers) will need quite some months before the machines are ready to ship. So the later the date, the more likely it is to be right.

December 1 hits the spot. But you don’t need a Microsoft hint or simple “iteration” to work that one out.