There has been a form of innovation - in some server farms that consist of thousands of interchangeable computers, they simply don't try to cool them, and instead just exchange air with the outdoors (possibly with a bit of filtering). If your software doesn't mind having nodes frequently drop out due to overheating, then it apparently is cheaper to replace melted CPUs than to keep them all cool.
Which is also why more data centers, including Google data centers, are being built in cool climates. If you're exchanging for cold outside air, you get to keep more of your servers from melting down without paying more for cooling.
http://blogs.technet.com/b/msdatacenters/archive/2011/01/04/...