In principle yes, though I'm not sure that all aircraft have it in all economy class seats yet. From http://www.cathaypacific.com/intl/in...on/0,,,00.html Inflight laptop power
Need to keep your laptop computer running at full speed onboard? We offer you inflight laptop power! This service* is available to all passengers in First, Business and Economy Class.

Inflight laptop power is available to passengers on a shared basis. Fleetwide installation is expected to be complete this year.

"The power output is 15 volt DC (75 watts). To make use of this service, you need to have your own universal air power adapter that plugs into an "empower" socket. This is different from your terrestrial power charger, and can be purchased inflight or on the ground at any major computer store."