All,
  I am not sure what kind of pandora's box I have opened.

  So, I have two gamers who are still, more or less, into traditional gaming. I am pretty sure at least one of them has never played anything with light rules. And neither of them have played anything "indie."
  And, they put their heads together and decided to both play Elves. Initially, I was OK with it. But the more I thought about it, the more it felt to be sort of against the spirit of the game.
  Their concept is this: Each of them is a reflection of each other. And so long as that illusion is maintained, they can tolerate each other as a reflection of themselves. They both have an "eternal question" and those questions are compatible ("What is good" and "Is there good without evil").
  So, I thought about it and I only came up with two doubts, which I asked them to address:
1) Both of these characters do not conform to societal norms for Elves. How is it that they are both adherent in the same way at the same time?
2) How do you translate these high-minded concepts into character actions.

  I did not get satisfying answers:
1) you (meaning me) don't understand, its totally logical philosophically
2) they will react to what they see

  I have decided to let it slide, they are likely playing the only two elves in a very large span of territory, so unless they go globe trotting, I don't have to worry about playing an elf that conforms to their bizarre pattern. And they can decide what their characters are like in play, lots of players have done this successfully.

  The question I have is, am I doing it wrong? I am out of my comfort zone here, so this is a serious question. If you see a flaw in my approach, please let me know. We are going to finish chargen tomorrow (Tues the 16th) and maybe do a scene or two. By next Tuesday, I need a pretty solid plan as how to approach this enigma.

Dave,

That actually sounds pretty cool to me! It sounds interesting, unusual, and potentially fruitful.

The part that worries me is that it sounds like YOU're not into it. Can you think of any relatively minor modifications that would make this duo palatable to you? Who knows, maybe the players would be totally with it.

Also, it's really hard to say whether this is a GREAT set of characters or a lousy one, because we don't know anything else about them:

* What are their Keys and Secrets?
* Important/significant background or personality information?

...and we don't know anything about the context:

* Where is the game taking place? What is the premise of the game? What kind of situation are they going to embroiled in?

With those in place, someone may be able to give more specific advice.

Paul,
  OK, yeah. I admit, its not clicking for me. They read the manual (hooray!) but interpreted it differently than I did. So, the only recourse I have as SG is either:
1) Let them be the entire population of Elves in the nearby vicinity (reasonable, but limiting for me)
2) Play an elf that does not fit their preconceptions of what these elves are.

  I have resigned myself to just not trying to play an elf myself. I wasn't really planning on playing one, but it is limiting none the less.

  Their characters are here:
http://casualgamerscorner.pbwiki.com/TSOY
  Its John and Chris

  This game is taking place in a Maldor city at the crossroads between a river-based trade route and an overland-based trade route. It is also on the border of Ammeni.

  I am trying to be laid back about it, but when I ask questions about their characters I just get a bunch of psychobabble and no real meat to sink my teeth into. I think with Chris, that comes from the fact that its not his original idea. But with John its more frustrating because I know it was mostly his idea, and he is getting more mileage out of making himself seem smarter than me than telling me, practically, what his character will be doing in this setting.

I'm also all for this concept - or would be if I knew the players and were actually in the game with them. Not our place to be in favour or disfavour of something we don't participate in, but from what you told that is a fun character concept those guys cooked up.

My method, were I the SG, would be to take the characters at face value and be sure to reflect the players in communication - talk about their characters, narrate what they seem like in the setting and give them opportunity to show their nature, then follow up with real consequences based on my own setting understanding. I often go into games without really understanding what a player is looking to achieve with his character, and that is fine with me; I don't need to know that, I just need to know what we've agreed about the factual capabilities and position of the character. As long as we're both fine with the character not being able to (or being able to) fart lighting and him being an elf (which has certain psychological implications), it's the player's problem how to play the character. This, of course, assuming that the player is going to play a protagonist in good faith and not just take a piss all over the game.

Did you use the Solar System chargen method, by the way? I'd be interested in knowing what the heroic events of these characters were. That is usually pretty instructive as to how the player imagines his character to be a protagonist.

Also, one another thing: embrace players who don't yet quite know what their characters are about. Solar System is uniquely suited to growth stories. The onus is on you to describe a compelling situation with compelling supporting cast, and then let the players get involved. It is well possible that a player doesn't yet know what his character should be, a hero or a monster, but if you put the character into position and let him act, he'll be doing things and gaining experience, and soon enough the player will start spending it. What will he shape his character to be? That's the answer to the initial question.

Eero,
  I used my lifepath system I created. It worked wel, gave me great inside into the character's past.

  Honestly, I am trying to go with the flow and get excited about the concept. It just concerns me when I get the runaround when i ask a question. They tell me that thy have a well defined concept, but when I ask for details, I don't seem to be getting a straight answer.

  OK, so nothing in the rules is broken by two elves. So, I'll stop worrying about that and concentrate on our communication.

  Thanks guys!

It is an interesting but complex outset that relieves you of the necessity to put other elven SGCs into play, as you will get all of elfhood out of these two in contrast and reflection. Big win, I would say, but with the same caveats as Eero.

If these players like a challenge, give them situations may just develop into either perpetual suffering or in one (or both) characters giving up elfhood… how that would be possible is highly dependent on campaign scope and player peculiarities and something you might only find out by riding the shockwave of two elves in/as one group.

(Did you look at the character sheets? I love how only one of them has the Secret of the Polymath. Perhaps the other is too young? I also adore how the initial idea of mirror couple has the potential to turn into a dysfunctional elven romance - how else would an elf understand love?)

It's the party structure that worries me a lot more than having two elven characters, really. Elves are difficult for parties, obviously enough. So stay on your feet, and if I were you, I'd be open to the party exploding to different directions if the players feel like going that way.

All,
  OK, so last night went well. Only one elf player showed up. But the one I was most worried about is the one that showed. Despite a high minded concept and making an assassin, he worked and played well with the group and the setting. He scored 8 xps last night and he was really trying to work his keys and still click with the group. It was fun.
  I guess for clarity, we have 4 players and a SG now. I am a little worried about the chatter on skype with 5 players, but with 4 it was manageable.

  I'll keep you posted.