None of the links implies when this phone will actually be available. For example Amazon Germany does tell us that Sony's Xperia Z sells for €629 and is available today at this price.
The previous HTC flagship, the One X+, now sells for €532 at Amazon or €499 at some other shops. HTC One X 16GB now sells for €363 or £314.64 at Amazon UK which is pretty good price for quite decent phone.
One can only hope that HTC One powered by Snapdragon 600 can come to market very soon, before people see what Samsung Galaxy S4 has to offer as usually the next generation Galaxy wins a lot of hearts.
You can find the HTC One listing here.