I like Nikon, have a few, will still buy them when they fit the bill. As Bigngreen said, if you want a lifetime warranty then you have to pay for it. I would not expect Nikon quality to suffer, but I would expect the price to reflect the change.
Things like are usually the result of accounting decisions. When you have a lifetime warranty, the liability on the books in huge and grows with every sale. With this accounting change, they just increased the book value of the company as the warranty liability will surely decrease.