It is unclear how much DL pays versus Gogo pays for the equipment on the plane. If Gogo funds a significant portion of the equipment cost then the approach taken makes a lot of sense - little outlay by DL other then plane downtime, FAA STC and related expenses.

Also, the trend in mobile computing is longer battery life. Netbooks have been getting 6+ hours for a year now and the new ULV promise 8 - 10+ hours.

By the time any carrier was to retrofit all seats to have power, many existing laptops will be replaced with newer ones featuring longer battery life. In 5 years it is likely that many people won't need power for a majority of flights. Why invest millions into something that may not be needed in a few years?