smells centralization...

Nope.
Just administration of the guarantee (the backing). Everything else is decentralized. The token still trades without interference from a central authority. But unlike bitcoin which has nothing backing it, Tether will have a pot of cash stashed away (with an administrator - hopefully trusted.) The admin won't be able to manipulate the token. The high level of auditing will assure the backing is well cared for.
looks good. but how is this different from say ripple and its gateway system? that could work pretty well enough if you accept tether as a good solution.
maybe what we need is something like nubits or bit.USD (afaik these two dont have counter party risk), but with a different implementation.
all in all, a pegged bit.FIAT could be the future.