Dan Lyke has a nice post about the real business advantage of open source.

If you're really interested in innovating, you need to be building these capabilities not on the advice of some 24 year old who just graduated who's been trained to be an Oracle consultant by parrotting their business process line, but on the hard-fought experience of your own company, and the wisdom of the people who've guided that company to its success.

And for that you need a software infrastructure that's agile, you need to be able to get into the guts of the processes that make your company tick and be able to customize your computer systems heavily. And to do that you need in-house expertise able to reconfigure and add features to your software. You need to nurture these abilities so that a VP can walk down to the IT guys and say "I was wondering, what would happen if we…".