The question in this case is whether the better olfactory skills of the police dog are like, or unlike, the eyes and noses of the officers themselves. The dog is not "searching" anything. He/she is simply smelling what is available in public. So, this is not an extra-ordinary decision or result.
Congressman Billybob
But what about Justice Souter's dissent? Does the fallibility of the dog make the search unconstitutional? Seems to me the defense didn't push this aspect hard enough...
But in Kyllo, the police were simply reading photons that were available in public, and the court ruled that they had violated the 4th. So there has to be more to the case than that.