Impressively faithful
I've heard this song so much I know it almost note-for-note, so I like to think I'd be the perfect judge for such a piece. And what a piece!
You've actually managed to get that all-important orchestral feel to it, which gives it that epic feel at all the right parts of the song. You must be using some pretty incredible VSTs. Must have been a bastard to render.
Some of the strings parts feel a bit too synthesized, which I'm sure could be tweaked by messing around with the velocity or expression of certain notes (for example, when you have the same note repeated over and over for a while, or that high-pitched strings bit just before the guitar part [which sounds particularly bad I'm afraid, maybe if you have it start off a bit quieter and build up? I'm not sure.])
All in all though, a brilliant remake of a track from a brilliant game. I look forward to hearing it with the fantastic guitar addition!