As the provider knows the serial number of both the STB and the smartcard, I cant see any problem with them 'wedding' the pair.
So long as they can 'software' it from 'On High' without doing a recall then I am sure they will.
Austar has done it with all their STB's as has UEC with their VAST stb's and Foxtel appear to be going along the same path.
The providers are there to make money and while no doubt they would prefer not to have to spend out to resort to these security measures, in the long term it will repay the cost by reducing multiple unpaid viewers and card piracy.
Maybe in five years or so, all these options like Card sharing and cloning/hacking will be just another entry on the page of Television history.