In case you people havent noticed it yet..or maybe im late on this topic i dont know.
If you look closely at the first screenshot..you know..the one with the scarab and the marines running towards it.
On the ground in the middle you can CLEARLY see an elite holding not ONE but TWO SWORDS!!!
is this a spoiler of the fact of being able to dual weild swords in halo 3???
Why else could it be there?!?
heres the link Dual Sword Pic