I am in Turkey at the moment and we just got power back. The most interesting aspect of it is that nobody knew what was happening and we didn't realise for a long time that the cut wasn't just local - because one depends on electrical means to get news a lot anyhow.
I think the cyberattack thing is a bit fanciful and that it is rather early to bandy that about. If I had a weapon like that I'd rather use it when it really mattered because after you use it once your opponent will wake up and fix up their defences.