I just stumbled on this interesting Blog post which compared the predictive quality of the Intrade prediction market to correctly predict this and last year's Oscars. It seems the market picked the winner correctly 11 out of 12 times.
Also interesting is the comment by BarTaxCa on the post, noting that depending on which prediction market one picks (HSX, Intrade, Inkling market) prediction differs. So it seems there is still a role to play for analyzing the wisdom of swarms through their Web buzz on IMDB and Rottentomatoes. In fact, what we found is that throwing the two together (prediction market + Web buzz) leads to the best results.