As far as I know, no other feature film has ever even shot a
single scene with IMAX cameras...The Dark Knight is the first.
So if you have seen a feature film in an IMAX theater and enjoyed it, then there isn't any reason you wouldn't enjoy seeing The Dark Knight in IMAX, which is what I plan to do. I always sit as far back as I can (which is funny, because I ususaly get as close as I can in a regular theater) and really enjoy most of the non-IMAX shot films I have seen in an IMAX theater. LOL, so I guess the answer to your question is "yes, I think it would be worth seeing in IMAX'.
By the way, there are
6 scenes in The Dark Knight that are shot with IMAX cameras (more than I thought).
Here is a really good 4 page article.