Yes, there are some troll references in the movie trilogy--are the extended editions the canonical version, or the theatrical release?--but what's a little lack of continuity to folks who put elves at Helm's Deep?
I think
Boro's point about the chapter providing an opportunity for a fight sequence is, very sadly, quite likely it's selling point for PJ.
The nonsense and light-hearted comedy (like that of Tom) could well be downplayed. The costumes of the dwarves in the snippets that have been released seem to me to be very dark. I had never imagined the dwarves all got up in black leather. Brown, yes, not not all black. (And miners don't get all leathered up while mining, as underground it is hot--at least the coal mines I have seen are, although weapon-making would likely require the protection of leather.) So I think
Esty's question about their portrayal is significant. If the chapter stays, but its style and tone are changed . . . .
I'm glad folks like the idea of thinking how PJ will depict each chapter. I thought it was a way to provide a new approach for a repeat reading of TH. Will try to stay tuned!