Well the one of the main reasons why Microsoft Server is doing better is because they have done 'partnership' deals with universities around the globe. Microsoft Server has been made a compulsory module in most of the Network Administration courses and then of course, there is that if-you-pay-for-something-its-got-to-be-good factor.

Its much like Oracle VS MySQL. Both offer high-end services, one has to be paid for and the other is free and open-source. To be honest, I think there will be a big bang soon in the Open Source industry, because Google is really interested in it.

As for the stats, I really don't believe them because firstly, people like me (and I have 6 sites running) did not post their 'votes', just to look at a handful of people and come up with a 'market-leadership' report gives me an impression, the site where you got the update from is just trying to get some extra traffic. Nothing more!