These are not facts, but my impression was that the B777 has power in Business. Either 110 or 220V (I'm not sure) and multiple connectors for different standards (EU / UK / US?). Basically you can plugin anything that has a standard connection. I don't think it has lighter-like connectors though.
For the KLM B737 I am always able to plugin my laptop or iPad using the standard european connector. I don't think this would be different for the B777. In Business though, as Europe does not have power as far as I know.