I'd be the first to vote those scenes off in exchange for the Ents sending the trees to Helm's Deep. I would have loved to see madness envelope the Uruk-hai as described in the book.
Honestly though, they were somewhat necessary in that they explained what Arwen is giving up, they showed the future loneliness she would face and the pain of a father becoming second in his daughter's heart to another man. It made Elrond seem a little more human.
Our problem is that we've read the books and all that is common knowledge. We don't need PJ to explain it to us. But, we have to try and remember that not everyone has read Tolkien and PJ has to baby-step them through it as well.