In the old days, when you went out to get IT infrastructure, it was a black box and all you worried about was how much it cost and what its features and UI were like. If you asked how the software worked, or where the data was or what its format was, you were told not to bother your pretty little head.
These days, interoperation and integration are everything. You'd better have open interfaces, open networks, open services; that is, open data. Which in practical terms usually means XML.
Couldn't agree more.