CTO of Applied.net sounds off about IIS 7 in production.

" I can say with confidence that we currently run IIS7 in production with Kayako Support Suite and it is extremely efficient.  We have always suffered with the challenge of deploying multiple server platforms in order to achieve a specific functionality from a php based application. This is no longer the case thanks to IIS7.   This  also means that “hybrid” developers will finally have a unified development platform."

Really, when I talk about IIS 7 being better, I'm not just making this stuff up.

Web Host Industry Review | theWHIR Blogs : The Skinny on IIS7