That doesn't really matter if in the PHP and .NET world you have to filter through 10,000 people to find somebody of the same median grade as you'd find in haskell/python/ruby/clojure.
I'm exaggerating for effect, but the take-home here is that if you don't have unlimited resources you need to have some way to differentiate and filter from the guys offering the sweet vacation packages and steady career options.
How exactly are you differentiating and filtering for higher quality people if not by technologies and developer freedom?
Do you have nice offices ala 37signals?
Are you an advocate of developer 'rights' such as Joel has been known to enumerate?
Why exactly should a dev tolerate using VisualStudio and Windows for the sake of working on your company?