Why not ask their sales dept?
Nothing is officially published yet, not even a release date. That's part of the Apple marketing magic to not disclose anything.
After all, the factory unlocked iPhone4 only came out in June 2011: http://news.cnet.com/8301-13506_3-20070980-17/apple-starts-selling-unlocked-iphone-4-for-$649-$749/?tag=mncol;txt
So they might very well decide to wait half a year or so with selling unlocked phones.
<span id="INSERTION_MARKER">will there be any factory unlocked iphone 5s in US in October or not? <span id="INSERTION_MARKER">