That 7 - 8 billion gives Time Warner like 20 years worth of rights. I'd guess its a lucrative deal no matter what happens, but there are so many variables in play - including big ones like inflation - that I can't imagine how they actually price it logically.
But look at the biggest deals in baseball finances from 20 years ago and the amounts look puny in today's terms. Economic growth has been massive in baseball, and given how bullish the corporate world is regarding sports, there could still be tons more growth.