From the Nokia blog entry:
We are very pleased to be able to confirm that Nokia TV, the latest Lumia entertainment offering from Nokia following Nokia Music and Nokia Reading, will be introduced in Finland in the coming weeks. Like Nokia Music and Nokia Reading, Nokia TV creates a free signature hub experience for catch-up TV services.
When the service launches, users of Lumia smartphones in Finland will be able to conveniently browse or search through the available catalogues of catch-up TV services from major local broadcasters and then stream a chosen show directly to their phone – without any sign up or registration.
There's no sign up or registration involved, so presumably checks are made via the micro SIM that's registered inside the phone.
There's no word yet about how likely Nokia TV is to come to other countries - we're guessing that we should all consider Finland a beta test of the concept.