According to rumours a few people here may care.
So, I this GA thread mentioned at Eurogamer, supposedly featuring MP details a beta tester dropped in the official forum - the original thread got deleted meanwhile.
Differences and new stuff:
-You can jump higher
-You seem to throw grenades a little shorter
-You can see your feet
-You see your shields spark and crackle when they are taken down, and you see a ring similar to the one at the beginning of PoA when they recharge
-All weapons have more than one melee attack
-When scoped in with any weapon, it has an ammo count in the scope to tell you how much is left.
-All weapons aside from scoped weapons have binoculars.
-Hijacking vehicles is hard but awesome. And I mean awesome. It's like. knifing some one on Counter Strike.
-When in the warthog passenger seat, it is a third person view instead of FP, making it much easier to aim.
-The warthog handles better, and the right trigger is a horn and the left is a brake. It DOES NOT have a boost.
-The Ghost is still awesome and has unlimited boost.
-One strange thing I noticed was that there is no fall damage, but that is probably just the beta.
-The HUD is completely different. The health bar is now vertical, and is above your radar in the lower left hand corner. Your right-handed weapon has taken the health bars previous spot, and the left-handed weapons info is in the upper left hand corner. You also can see what your reserve weapon is. In the bottom right hand corner is a score keeper, a red bar and a blue bar that show the difference between kills, flag captures, etc. This allows you to quickly check the score without having to press back.
-There is no more health. Once your shields go out, you can take three or four more shots, but there is nothing to indicate how much health you have elft.
-Frag grenades don't look like pineapples anymore.
-You move slower while carrying the bomb or flag, and must hold x to pick them up.
-Spartans and Elites grunt in pain when they are it with no shields up.
-Halo 2 will support four people on one Xbox for LIVE play. All at the same time. In case you didn't here me, I just said FOUR PEOPLE ON LIVE AT THE SAME TIME ON THE SAME BOX! How awesome is that?
-There is no flashlight it is now a teamspeak button.
SWORDS- Yes, there is a swords only game type. 'Nuff said.
ASSUALT- This is not like the assault with flags. This one is done with bombs. It is a lot like bomb maps on CS. One team is on defense, while the other is on offense. Some one on the offensive team must pick up the bomb, which is like flag in that you can melee with it but can't carry it and use guns at the same time. The offensive team must then escort the bomb bearer to the defensive teams base, plant the bomb, and prevent the enemy from defusing it. You defuse by simply standing on the bomb. After the round is over, the teams switch roles, like one flag CTF. It is really an awesome
Plus descriptions of the weapons, some maps and whatnot.