My wife worked with someone named Arwen, who was quite happy with her name. Of course, she was in her 20s by the time the movies came out, so that might change the dynamic somewhat.
I named my daughter after a Fantastic Four supporting character, but worried because it was shared by recently (if perhaps temporarily) popular celebrities -- who I have nothing against, but didn't want it thought that we were the kind of horrible people who name their children after actresses and singers (rather than blind sculptors). There might be a larger cluster of girls with the name in her age bracket than we'd like, but everyone seems to pronounce it differently anyway.