Anyway, time for me to spill some beans:
*There will be double weapons.
*There will be a useable energy sword...and...wait for it...double energy swords! Harder to use, but effective.
*Enemy AI improved, maybe they will search around areas.
*Original maps for multiplayer, like a volcano area one.
*More than two types of grenade.
*Maybe new vehicles, but i need ideas.
*Multiplayer split screen should definitelty be in version 1.0, and online play, if it arrives will be in version 1.5.
*Thanks to Sepiku, there are new and better sprites, although the Grunt and Spartans probably will be the same.
*Vehicles should be destructible.
*Plasma grenades will stick.
*Maybe a pilotable Pelican by default.
*There will be tons of minigames, most of them hidden.
*It will come with some cool artists MP3's in the multiplayer soundtrack (probably).
*The download should be pretty big, so if you are on 56k, i may be able to mail it to you.
There will be more, so i'll update if i remember them. Too bad this game that i've spent about a year on isn't getting as much attention as mods that took about 4 hours. Sure, MonoxideC has done plenty for us and got $1000 dollars on the library, that took him a couple of months. But a year?

( if you do not have the beta demo, get it here: http://www.halo-scene.com/download.php?view.154 )
Thanks for reading, expect screenies soon, and perhaps videos.
~Spartan III