On 15th November 2007, Universal announced that filming of the Cirque Du Freak movie would begin in February 2008. They also announced the names of the first three actors cast in the movie. Here is one of the many media reports of that announcement.

ENTERTAINMENT WEEKLY - 15//nov/2007

Universal Studios has given the greenlight to an adaptation of Cirque du Freak, British author Darren Shan's hair-raising children's novel that is the first of 12 installments (can you say franchise?), to be directed by Paul Weitz (American Pie) and possibly star John C. Reilly. The Walk Hard actor is in negotiations to play vampire Larten Crepsley, a member of the circus who becomes intertwined in the lives of two young boys. Josh Hutcherson (Bridge to Terabithia) and newcomer Chris J. Kelly are in negotiations to play the two boys. Production is scheduled to begin in Feb. 2008.
Three of Shan's 12 books have already been optioned by Universal, and J.K. Rowling has endorsed the fantastical series. Cirque du Freak marks the second venture into the big-budget children's movie biz for the Weitz Brothers: Paul's sibling Chris will show his mettle next month when New Line bows his $150 million budgeted Golden Compass — another movie with franchise potential.