Can you link to where it is available? If I google for bt smart hub then the first link is to the HH5 on the BT site and the second is the ISPReview article saying that BT were looking for trialists to sign up with a closing date on sign up of early June.
BuckleZ (fountain of knowledge)
Thu 16-Jun-16 14:02:05
It's not yet on the BT SHop website, but if you check the BT community forums customers have been offered this when re-contracting. I do believe offical release is today... so expect on BT shop soon...