Rhythm and tempo will change, with books it's ultimately me who dictates the pace.
I understand what you mean, but I'd argue that the books have a natural pace dictated by both the dialogue and sequence of frames which HergÃ© choses to draw in a given scene. And comics are - like film - a sequence of frames. Comics are like snapshots of a film in a way. HergÃ©'s work is almost completely dialogue (and pictures of course), with very little narrative. Compare to Blake and Mortimer, for example, where there is lots of descriptive text in the frames which slows the pace, for me at least.
Of course, most books (not comics) are usually mainly narrative, so there's always a chance that they're not going to match up to your own mental image when you see them in film. (By narrative I mean, not
dialogue, but it's probably the wrong word...) Also, the appearance of the Tintinverse has already been well defined by Hergé, so (hopefully) the look has been taken care of in the film.
By the way, I'm not trying to say that anybody's opinion is wrong; I also have doubts about whether I'm going to like it. I've not seen an adaptation so far that comes near the books, although I have quite enjoyed some. I'm just being optimistic and pointing out that there isn't any reason why the film shouldn't be a resounding success in its own right. Maybe in years to come most people might not even realise it ever was a comic, just a series of films. Or maybe after they've made a musical, like Annie
;-) Now, how many kids today would know that Little Orphan Annie
started as a comic strip?