The other day when I was putzing around and completing a few quests around Thousand Needles, Murtaugh and I were keeping a running conversation going. (He was over in one of the higher level areas; more than high enough to be instant death for a 31st level Paladin.) Anyway, during the course of the conversation he asked me whether I'd be playing the Horde if he and Missy weren't already playing that faction when they invited me to join. I rather quickly tossed back the reply that I'd probably be playing an Elf of some sort, whether Horde or Alliance, and gave as my reasoning that I've played enough Humans in my past that I'd like to try something different.
After his query fermented in my brain for a while, I thought it deserved a better answer than that.
Of course, the flippant answer would be that I wouldn't be playing WoW at all; I had no real desire to go play an MMO before being invited to do so. The 'why' of that is simple: MMOs are not what I typically play when I play computer games; I'm much more in the mold of the turn based strategy player. Civ is probably my favorite game, but the Total War series is also damn good. The old Master of Orion was great, and it sounds like Galactic Civilizations II is following in the same vein. Sure, I'd played computer RPGs before, but not MMOs.
Now, putting all that aside for a moment, what would I play if I decided to try out WoW on my own? My RPG history suggests a Human Priest or a Human Warrior, but in reality I'd kind of tired on playing Humans. The natural extensions of a D&D player interested in fighting would be Dwarven or Orc Warrior, but I wanted something different. The Elves of both sides are appealing to me, mainly because they're different from Humans but not too different to play well. (Yes, I slip into FTF RPG mode when I consider characters to play; kind of hard to disassociate myself from something I've been playing since 1980 or so.) The thing about Elves is that, well, they're popular. Blame the Lord of the Rings movies, the Cult of Drizzt, all sorts of generic fantasy worlds, or even D&D, but Elves are hot. For a guy who prides himself on marching to the beat of a different drummer, following the pack wasn't exactly what I had in mind.
Two things made me stick to my guns: just because everybody else does it doesn't mean that I shouldn't, and in an MMO you can make your own path. Do your own thing, don't be an ass, and you'll be fine.
Now, the question becomes Horde or Alliance? If I'd have just seen pictures of the races and made decisions that way, I'd probably have chosen Alliance. Come on, I'm programmed just like everybody else to think that the side where Humans, Dwarves, Elves and Gnomes are on is the "good guys" side. When Murtaugh and his wife invited me to join, however, I took the time to read a bit of the history of the races. Blizzard did a great job of making the backstories neutral enough to keep it from being slanted toward one faction. There were enough bad and good deeds all the way around that kept one particular faction from being easily defined as "the good guys". Digging down, you find the stereotypes of the Horde races don't fit; sure, they don't like the Alliance, but that by itself doesn't make them evil. (Okay, the Forsaken don't help themselves much with their tendencies toward eradicating Humans, I'll grant you that, but given the Scarlet Brotherhood you can understand the source of their dislike.) In fact, I find the Native American slant that Blizzard built into the Tauren fascinating. It's perfect in it's own way, taking what would be a stereotypical Minotaur and turning it into something else.
I guess the answer to the faction question isn't simple; I still might have chosen Alliance, but I'm comfortable with the Horde. Except for the Forsaken; even the rest of the Blood Elf NPCs seem to be a bit, um, uncertain about their erstwhile allies, but they play nice for the time being. The Horde seems to be a good fit for me right now, and I'm fine with playing it. While I might try an Alliance character later for comparison, I'm fine with playing Horde at the moment.