You could not have summed it up better with your title "Power to the Audience". The emergence of Web 2.o indicates a power shift between media producers and audiences, enabling the audience greater control over the media that they consume (Cascio, 2006).
In my opinion, this is a marketing trend that has been employed by media producers to harness the colletive intelligence of the audience, using these mechanisms to effectively generate material in favour of the audience (Jenkins, 2002). Who better to determine what we wish to consume then us??
Audience empowerment has stemmed from the ability to control what they watch. You raise good examples such as Big Brother and Australian Idol. These were shows by which the audience was given the opportunity to control the outcome of the show. Here we see the public shaping social views (produsers). The power, once in the hands of major conglomerates has been given back to the consumers, empowering them to participate and essentially develop the marketing concepts for them. The promise of participation helps build consumer investments (Jenkins, 2006)
The new digital environment has indeed expanded the audience’s ability to produce their own media products in combination with media producers. I do agree with your points that it is due to the expanding digital environment that has enabled the interactive audience and believe that as technology continues to evolve and expand we will continually see a power struggle between producers and audiences - perhaps a blurring of the line between the two.
Cascio, J. 2006. The New World, the Rise of the New Culture of Participation. The Institute for Ethics and Emerging Technologies. November 15, 2006. http://ieet.org/index.php/IEET/more/cascio20061115/ (accessed 3 April, 2008)
Jenkins, H. (2006). Introduction: Worship at the altar of Convergence in Jenkins, Henry, Convergence Culture: When new and old media collide, New York: New York University, pp. 1-24
Jenkins, H. (2002) "Interactive Audiences?" in D. Harries (ed) The New Media Book, London:BFI Publishing, pp 157-170
Jenkins, H. (2006) :Buying into American Idol: How We Are Being Sold on Reality Television," Convergence Culture, New York: New York University Press, pp. 59-92