Times have changed for IT. Is there really anyone who has looked at the consolidation in the IT market, the slowing of IT sales growth, the decline of IT profit margins, and who hasn't realised something bad - at least in relative terms for the IT industry - was happening? Microsoft and Sun Microsystems are becoming friends, for crying out loud.

IT has been wildly successful insinuating itself into every aspect of business life, and it will continue to do so. The developing world remains a great market, and selected industries - healthcare is a big one Carr rightly identifies - still have far to go in adopting IT. But much of the IT build-out is done. That includes hardware and most software. For both IT purveyors and IT users, figuring out competitive advantages based solely on the technology is difficult. It always was, but the rush to not be left out of the wiring of the world kept the corporate IT buying engine stoked. So is the notion true that IT has run its course as a source of competitive advantage, as Carr suggests? Good question. For the kinds of tasks we've come to expect from IT, the answer is probably yes. Carr also argues that the ubiquity of IT supply means that even for tasks we haven't thought of yet, IT can't deliver persistent, competitive advantage.

Maybe. But unlike gas, water, and electricity, IT is remarkably malleable. We have no idea what's next. At a minimum, IT will continue knitting together business and society in ways that are familiar and addicting. It's also likely that unexpected surprises are ahead, and who knows what competitive advantages they will bring. The market will tell us.

Carr's book isn't bad. It's often interesting, just not profound. How much you learn depends on how closely you've been watching the IT revolution.