I'm keeping it on my radar due to cost differences in AWS. A .net web app using 4 EC2 m3.xlarge instances (2 front ends per AZ) would save over $6000 per year in hosting if using Linux AMI versus Windows.
Yes, the Windows tax is not cheap, nor are they nearly as easy to clone and manage in a virtual environment. Linux is simply a superior server in virtually every conceivable way but most especially financially.