I'm not sure, but I believe the next Vampire Diaries book, Midnight, may be the last, and the author has implied that Elena will finally make a choice between Stefan and Damon.
Most of the people I've come across believe that Stefan/Elena is a sure thing, however I don't believe either guy is a sure thing. Now, personally, I ultimately 'ship the threesome, I don't see why Elena should have to choose. The origin of the plot is that Stefan and Damon really mess up their lives because they both loved a woman and could not live with sharing her. It seems to me that the most appropriate conclusion is that this time they learn to share. I could go into a longer explanation of why I like them as a threesome, but it comes down to that. However, LJS seems a bit traditionally-minded - in the books vampires don't get erections and every remotely sexual scene fades to black so to end with a threesome seems too extreme for that kind of person. Which is, sadly, most people. :( And given that the intended reader is teenaged, it bucks the norm even more.
So, if you take out the possibility of a threesome (which would be a very pleasant shock for me, if it happens), I 'ship Damon/Elena. ESPECIALLY in the bookverse. Stefan is a mostly very cardboard character, almost flawless, and his relationship with Elena has honestly been pretty smooth. In other words, it's a really fucking boring story, when you look at just those two. And every time Stefan calls Elena his lovely love and they stare adoringly into each others' eyes for twenty minutes, I kind of want to set things on fire.
In general, books don't usually have the woman hook up with the guy that it seemed like she was going to be with at first, (otherwise where is the story?), so that is a big sign, to me, that it will end Damon/Elena. The Damon scenes have been slowly building, and we might just get the big payoff in Midnight.
On the other hand, I have this horrible foreboding about the next book. Damon is now human. He can now have sex with the virginal Elena (and they keep harping on this virgin thing lately). He can get Elena pregnant. And I think he's suddenly going to be feeling really guilty about his past (kind of like Spike in Btvs Season Seven). If Elena hooks up with Damon because they're going to have a baby together, or because he was the one to take her virginity, I am going to feel really unhappy and nauseous. I don't want Damon to somehow turn into nu!Stefan and for this to all end like the worst kind of cheesy romance novel. If it's going to end like that, it better be Stefan/Elena.
I also feel conflicted over the book ending Damon/Elena, because then it seems less likely that the TV series would go the same way.
The way they handle the relationships is a big part of why the TV series is fast becoming much favored over the books for me. The vampires can have sex, and Elena has already slept with Stefan and is obviously staying overnight with him occasionally without making a big deal out of it, or even mentioning Elena's virginity. (I suppose it is possible that Elena and Stefan haven't actually gone as far as full on penetrative sex, but I doubt it. It's possible that Elena and Matt had sex before, but it doesn't seem very probable given Elena's comment that Matt didn't make her feel real chemistry. So I applaud the show for not making a ridiculously big deal out of virginity loss.) This Stefan is a bit darker. Actually, this Damon is considerably darker, as well, perhaps even problematically so, as far as future romance goes. One interesting twist is that in the books, sex is a big deal. In the TV series, biting is a bit deal - unlike in the books, Elena is not a regular or semi-regular blood donor for either vampire. Unless things change, Stefan (TV) doesn't have the self-control to feed on her safely on a regular basis. Damon, however, does, and I suspect this issue will come up at some point next season. Especially if Jeremy/Anna will continue on for awhile longer - it's clear that Anna could regularly feed on him more or less safely. Actually, I hope to see this, I'm not sure I've seen more than maybe one or two vampire stories where a female vampire was the dominant in the relationship and regular feeds on a male character, it's a refreshing change. I really like their relationship, although I look forward to seeing some Jeremy/Tyler later (it seems strongly foreshadowed to me).
I find TV Stefan/Elena less grating on the whole, but I still find it a bit boring. Damon and Elena are interesting due to many more conflicts. Elena is a more good person in the TV series, while Damon is more of a cold-blooded killer. Still, just like in the books, Damon feels compelled to treat Elena with honor 99% of the time, unlike any other person he interacts with, and they are strangely insightful of each other's deepest feelings - in a way that Stefan is not. I'm happy to see the series retained this very important quality of their relationship.
Although Damon is evil, most of his kills are vengeance related. If you cross him, you die - even if the slight was not deadly serious he will take it that way, especially if you mean nothing to him. Unless it's a totally impersonal "food" killing, he always lets the other person make the first move. For the people he likes, he will satisfy himself with fucking with their head, teasing and taunting, and saying cruel things, and lying (though sometimes he is lying to himself as much as to the other person). In many ways, he is a strangely honorable killer.
I felt conflicted about it at first, but I think I quite like the way that slowly most of the town is learning of the existence of vampires, etc.
As for Stefan/Damon (or vice versa ;) ), I'm not opposed to the idea, but it's not my main 'ship. I can't see it as a regular thing, honestly, not like with Sam/Dean. The Salvatore brothers have a far more hateful and conflicted relationship, and while they have their own kind of codependency, they have possibilities of other pairings working out for them, patently unlike the Winchester brothers, IMO. It's interesting how sexually charged those flashbacks of them just being turned were though, LOL.
Slightly spoilery for the books:
Also, Bookverse fans: L.J. Smith is having a contest on her
blog for a gorgeous dual kitsune ring or one of twenty autographed Shadow Souls. *WANTS*