I'd like to say Yay!...but Tintin is a very un-P.C. character for Spielberg and Dreamworks to tackle without major revision. Time will tell.
Thinking about it a little, I think they'll probably decide to do a live action film, write their own Tintin storyline and place it in modern times, which would kill the charm. I very much doubt they'll luck into a number of Tintin diehards in Hollywood who'll fight to protect the integrity of the adventures.
I remember the animated series from the late sixties, which was faithful to the original material. Hollywood can in no way improve upon Tintin. My recommendation is to pick up the original cartoons, which are available as compilations of three different adventures. Tintin in Tibet was Herge's personal favorite.