I think they will downplay it and cut the relationship development in half. This is all supposed to be from Harry's point of view, and from what I've seen so far, most of the Ron/Hermione parts have been cut anyhow. I wouldn't be surprised if everything is just mentioned in passing. Something like Harry and Ron talking about Lavender; or Lavender and Parvati talking about Ron, and Hermione overhearing it.