Contains an embedded reference to SeatGuru's reference page on the same topic:
The next time someone tells you a particular innovation is impossible, contemplate this gem from 2010:
"Simply put, the plane would be too heavy to take off. So claims various readers of The Atlantic, who wrote in after adding up the math and coming to the conclusion that to offer 120V AC sockets to every person you'd need "the equivalent of ten or so Chevy Volt batteries, and an inverter the size of a large refrigerator." This is if every person was using 2 amps of power over an eight hour flight, so it'd obviously vary."
Cuz, I mean, it's not like there's a fuel burning engine on that plane that could produce electricity.
Also, batteries have been shrinking for a while now.
Adapters are provided for some situations (plug has a sleeve, British users, etc.)
Things have clearly progressed since 2006:
A bit more about changing standards:
ETA still more: Not about power outlets, but about the last pre-BYOD IFE systems, and how it replaced the black boxes with fiber to supply the bits direct to the screen.
ETA: Outlets AND portables on Alaska Airlines
That's the full solution: outlets, wifi, content that is available on a provided (for a fee) in cabin device OR the one you bring yourself.
JetBlue's offering, and their negative remarks about GoGo and Row44:
We're really deep into Coke vs. Pepsi here.
According to the NYT, the massive failure of seatback phones is why IFEC has been slow to get going. I remember seatback phones. I don't think I ever used one.