I think that Amazon is content to let Zappos experiment. If Zappos loses customers, statistically most of them will end up at Amazon anyway. Tony Hsieh is pretty out there, and a lot of his ideas sound kind of crazy, but I think Bezos believes in him and is willing to let him try. Even though everyone says "Oh, that won't work" you don't know until you try.
If Zappos can experiment with a new leadership style, maybe it produces desirable results that can be replicated elsewhere. Maybe it fails miserably. What's likely to happen is that there will be things that work and things that don't, and I guarantee Amazon is interested in that. Because of all the things I've heard about Amazon (many of them good), I've never heard that it's a great place to work. Their turnover is high, so maybe they're looking for ways to reduce it while not losing the culture of urgency (though some would say fear) that makes them so good at executing on things.
Of course, if it's a total failure, Bezos will likely fire Tony and trash the entire idea.