I saw Adventures of Tin Tin a few weeks back. It was pretty awesome, actually. It was primarily an action-flick, which somewhat minimized Tin Tin's detective work, sometimes more diplomatic approach etc. that is more heavily emphasized in the actual comics. On the other hand, there was some truly hilarious slapstick and, as Bob said, no shying away from the more violent aspects of the comics as well.
Some people hated that the movie basically mushed several comics into one, but to be honest, I haven't read all that many Tin Tin comics, so maybe that's why I didn't mind. I simply don't know them all, so the mushing that has been going on was somewhat invisible to me, when a die-hard fan would probably get pretty pissed by it. There were one or two scenes, including one particular fight scence close to the end, that I didn't like, but all in all I enjoyed the movie a lot.