None of the stores has given a specific launch date for the smartphone, and there isn't official confirmation of the availability in Britain from HTC either. The initial information that we got after the announcement said the international rollout will happen this September, while limited markets will be getting it as early as August.
Both black and silver flavors are available for order. If you are interested in the 4.3" One mini now might be a good time to book your unit. Meanwhile you are welcomed to check our preview of the smartphone.