I was on the original (well first I heard of) mobile TV trial which Orange ran nearly 3 years ago, which I assume ran over 3g somehow. After the 3 month trial period, they then wanted 10 quid a month for the service! (and that was only 9 channels IIRC)
Laugh? No, I just canceled the service.....and then rang up to cancel again, after they charged me anyway!
I can't speak for others, but I'd be prepared to pay 50p a month for access to mobile TV, and only then if it included worthwhile channels. Any more than that, and they can keep it!