Actually, Tolkien said in his memoirs and other places that he always wanted to expand Arwen and Aragorn's love plot, but couldn't figure out how to do it without changing the tone of the book... women weren't his strong point, so he gave up. I think he would approve. I don't like the idea of her as another warrior princess, since that steals Eowyn's thunder, but I think if it's done well, it won't be THAT bad.And accents.. are just tags we mentally assign people. What matters is what they say. I, for one, am looking forward to the movies...
-J