Sure, but that doesn't explain why they show the USA jumping from 27.7% to 38.7% in one day (5/24 to 5/25) when Google's numbers don't show a similar rise.
You see the same jump at the same time in some other countries, such as Norway and Canada. I would guess that's down to a measurement adjustment on the part of Akamai, enabling them to see more adoption that they had been missing.
You might be using IPv6 and not even know it (if you have a smart phone or residential internet access, chances are that you already are using it). And that's how it supposed to be, it would never be a concern of a user.