I was just writing about this very topic, http://bit.ly/aafJBI. This is the same point I've made many times to clients and the public alike, and it's always certain to raise some hackles with the OS partisans. I too am a fan of OS, in fact I serve on the advisory board of one, but it's just one set of tools in the toolbox, and you'll never know which is the right tool if you don't thoroughly know the problem. And TCO is a huge part of whether a system is ultimately considered a success three or fours down the road.