Bombadil's character dominates his chapters, and does not substantially advance the plot. The Wild Men are just another group of good guys, who are a good explanation of how to get past the guard at Minas Tirath.
Does anyone know if they are going to include the 'undead' warriors, the ones who were called to fulfil their oaths. They were creepy, but were a good way to remind people of the level of crisis that Middle Earth was in, and the penalty for not doing what you had sworn to do. Would kind of like seeing X-42 as one of these perjured chiefs, at last earning a peaceful repose.