It's all part of the bitshuffle.
Is that change, or a legitimate micropayment? Who knows... Bit-shuffle! (it's for anonymity)
It doesn't really improve anonymity, though. In many cases, it's possible to determine with 100% certainty which output is change, which is not.
And it increases transaction size, as it adds an unnecessary output.
The only utility I see to it is that it fully spends the inputs, so the transactions which once filled them could eventually be pruned. But that to the expense of larger transactions. As I think bandwidth would be a more important concern for future professional miners than disk space, I don't see much of a reason for this change feature.
