It seems like all the pieces are falling into place, that the 5S available supplies on launch day are going to be VERY limited. Vodaphone and O2 say you won't be able to get them on launch day, but just order them. Probably the only real certainty is an Apple store, and then you better be early. In the US, I would be real hesitant to count on getting what I want at a Best Buy, Target or Radio Shack. They might get a few, but Apple is going to give most of them to the Apple Stores.
I have been in contact with a Verizon, non-corporate store and the manager will let me know when they have some stock. If I don't hear anything by Thursday evening, I am going to the Apple store, early. Be very careful about signing any contracts without the phone in hand. Some of these outfits want you to sign a contract and tell you it definitely will be in on launch day, then on launch day they tell you that they had a problem, and you will get in "soon".
I have been in contact with a Verizon, non-corporate store and the manager will let me know when they have some stock. If I don't hear anything by Thursday evening, I am going to the Apple store, early. Be very careful about signing any contracts without the phone in hand. Some of these outfits want you to sign a contract and tell you it definitely will be in on launch day, then on launch day they tell you that they had a problem, and you will get in "soon".