Accenture have published an interesting paper on "Why TV Advertising will never be the same again". There is little new here but it's a good summary of where we are right now. And given Ford just hired Accenture to advise them on their US media and marketing planning, their view is pretty influential.
Probably the most interesting opinion is that interactive TV will grow in the US, following the European experience. We agree but continue to worry that brands are not as involved in iTV as they should be.