It has been reported that the Windows Server family of products has overtaken Unix (that's commercial Unix, not Linux and other free OSs like FreeBSD) in usage. Now I don't like this statistic, probably because I'm a bit of a Linux person and I don't particularly want Microsoft to gain yet another monopoly. Microsoft already have a monopoly on the desktop, and I don't think it's beneficial to the world for Microsoft to rule over every server too. This is something I get quite heated about, not because I don't like companies from developing proprietary software, but I don't want one single software company to control the whole market share.
Interestingly enough, Linux actually is in third place, so it will be quite interesting for us Linux geeks to see if that market share grows, especially considering that Linux can be very cheap to implement in an enterprise situation.