Any way you look at it, this is great news, and it sets a wonderful precedent for other manufacturers of all sorts of electronic devices.
Lots of people are happy to be able to keep using a phone even if the battery is a bit degraded, and the fact that Google plastered this all over their marketing material means they have some legal obligation to follow through on this promise (or compensate their customers if they don't).
I am in awe at all the "I gave to my 8 years old daughter my original iPhone 1 and she's still delighted by it every day, it's stille great" folks.
You could put out a free device with a battery that lasts forever, fast and it fits in every pocket and some crowd woud still make comparisons and have some brand win them.