[Kalimac]

I don't think Arwen was a last-minute "Oops, gotta get Aragorn married off" thing, if only because there's that line in FOTR where they're all in Rivendell and Frodo sees a few significant glances pass between Aragorn and Arwen (not that she speaks, but in Tolkien's world, those glances are quite significant). Certainly she's less of a surprise than Rosie Cotton, whom we don't even get an inkling of until Sam starts thinking about her most of the way through TTT, and whom we don't even see until the end of ROTK.

I agree that she feels rather underdeveloped; we're being told that Aragorn falls in lifelong love with her at the age of 20, so clearly there's something there, but we can't see it (had to be there, I suppose). I don't think this detracts from FOTR at all, though, and the reason is that there's no real reason that we *have* to know - it barely affects the main story at all. Aragorn has already fallen in love long before the story begins, and their marriage upon his becoming King is pretty much a given; the only thing this *changes* for any character (except Arwen herself) is the fact that Frodo is now given Arwen's spot in the ship for Tol Eressea. That is an important thing, obviously, but even so, it's hard to believe that Gandalf or someone couldn't have finagled him aboard somehow even without that (after all, Gimli and Sam both managed later on without having any Elves trade with them). For this reason we only really need to know the basic facts; namely, she's an Elf, she gave up her immortality to marry Aragorn (parallel to Luthien - the circle is complete!), they had children, and later died. Since their mutual affection does not materially alter the course of events in LOTR in any way - nor does it drastically change their characters during these events - there's no reason we have to know every detail. (I'm speaking from a story-writing perspective only; from a personal perspective I wouldn't mind seeing more of her).

Faramir and Eowyn are different. First of all, their love story takes place right in the thick of the story's events, secondly, it changes both of their characters a great deal. Faramir, for the first time, is not operating with the constraint of his father and brother somewhere in his mind (not that he always did what they wanted, but they were still there); in essence his actions in the Houses of Healing are a sneak preview of what sort of man and ruler he will be on his own, and of course all signs are highly favorable. For Eowyn, she is transformed from a "caged" and frustrated shieldmaiden into someone who has a renewed love of life, thanks largely to Faramir.

Tolkien does not seem to have been a natural writer of love scenes, though I'd hesitate to ascribe it to his upbringing - after all, Ivy Compton-Burnett lived pretty much her entire life surrounded by women but still managed some fairly intense love scenes in her books. Tolkien may well have shot his entire bolt on the Faramir/Eowyn love scene; if so, it was well worth it. It's one of the best I've ever read.