Here is the sheet music I've been working on for a while. There is a PDF and a Finale file. The beginning is rather hard to see on the PDF because Finale's layering system overlaps notes in previous layers, making it difficult to distinguish, but you should be able to figure it out. Some of the chords in the beginning are also simply impossible to play with one hand, so you may want to just pick and choose what notes you want to play. This wouldn't have been possible without Andybeano's Tribute for Orchestra sheet music which I used to make the majority of this, adding a few changes here and there. Feel free to upload your own versions of the song based off of this, I just ask that you give me credit for the original piano piece as I credited Andybeano.

So here it is! Enjoy.

P.S. The time signature I believe is supposed to switch to 3/4 when the violin solo comes in, but you cannot change time signatures in the middle of a song using Finale, so I just kept going with it.

[update 1.2]
In update 1.2 I've included a "without beginning".mus and .pdf files for those of you who want to skip the ugly-looking and impossible-to-play beginning. The ending has also changed to what I believe to finally be the correct transcription, and that was all possible because of theawesome1 and his post of Halo 2's Epilogue.