Great quotation on the OSGeo-Discuss list:

The brutal truth is this: when your key business processes are executed by opaque blocks of bits that you can’t even see inside (let alone modify) you have lost control of your business. You need your supplier more than your supplier needs you—and you will pay, and pay, and pay again for that power imbalance. You’ll pay in higher prices, you’ll pay in lost opportunities, and you’ll pay in lock-in that grows worse over time as the supplier (who has refined its game on a lot of previous victims) tightens its hold.

I heard Chris Di Bona of Google say exactly this at a conference in DC last year with respect to Google’s own strategic software direction. For anything that is core to their business, they use open source if it is good enough, or build it themselves if it is not. Being beholden to a vendor would be a huge competitive disadvantage to them.