I once read in some arty film guide that there's essentially only about seven different types of film (genre) to be made. At its core, every film is basically one of these seven or so ideas. The only originality is in how you present that idea on the screen. Even when someone does come up with a new and ground-breaking way of doing this - say with The Blair Witch Project or The Matrix - every subsequent similar film suffers unfair comparisions and then, like others have stated, you either have to come up with something else totally ground breaking - which will make squillions if you pull it off or bankrupt the studio if you don't - or go with a tried and tested formula which maybe won't bring in the mega bucks (although you hope it will), but should at least make a pretty profit thanks to bankable stars and guarantees you at least one more job.
Also, I think it's important to distinguish between what is an out an out remake of an earlier film, and what is simply another filmaker's interpretation of source material which someone has previously commited to film, which someone touched upon earlier. GVS's psycho was the former. Tim Burton's Planet Of The Apes was the latter. Burton wasn't trying to update the 70's film. He was simply filming his interpretation of the novel. His Charlie etc will probab;y be along the same lines. Is he adapting the earlier film, or the Dahl novel?
