The article actually mentioned one Prius battery replaced due to "wear and tear", but in Australia, not the USA (so Toyota's affirmation that they haven't replaced a battery yet in the USA is still right).
That Australian Prius was a taxi and it ran 550 000 Km before its voltage became so low it had to be replaced. 550 000 Km represents, what, about 25 years of ownership for an average owner? Looks like those worries were greatly exaggerated (mostly by the anti-hybrid crowd), I'd even say that a gas engine in a normal car will likely break sooner than a Prius' battery will give out. I also remember those who kept swearing up and down that hybrids' resale value would suck, even a few years ago. Nope, their value is still pretty damn strong, I think the Prius is even amongst the cars that keep their value the longest.