While IIS may be a good system, which I can't attest to, having no experience with it, it's still reduced to the reliability of the platform on which it runs. Nix has historically, and probably always will be more reliable - a system running nix does not need to be rebooted as often as Windows, if at all (which again has been proven time and time again, there are people that have had nix boxes up for periods of well over a year or more without turning it off).

Microsoft is out to make money, and granted that may mean that they provide better support, but it's the money they're after. Open source, albeit chock full of amateurs (due to it's availability, of course), has always been about the software. I personally tend to trust somebody who is in it for the game, and not for the money.

I'm not saying all Microsoft is bad. I use it on a daily basis. But just because they have market clout and agents to run around and run spin control doesn't make them the king.
-m