Activision and developer Infinity Ward have released enough information on the Call of Duty 4 multiplayer beta to fill a six-page magazine preview (lookout for them in a month's time).
Straight to the chase... (note: all of the following quotes come from this website)
Experience points: "In game you are going to see pretty yellow numbers pop up when you complete objectives, get kills, etc. These are your Experience Points. Experience Points add to your overall ranking during the match. Depending on the matchtype, you will get a different number of points for different actions. And no, you will not be able to carry your rank over into the final game."
Does it have a party system?
Yes. "Select 'Xbox Live' from the main menu and then choose 'Find Game'. If you want to party up with your friends, select 'Party Invite' from the same menu. You can also jump into matches your friends are playing by selecting their gamertag through the Xbox 360 dashboard, Friend's List and the option 'Join Session in Progress."
Attachments: ACOG Scope, Grenade Launcher, Grip, Red Dot Sight, Silencer
Grenades: Flash, Smoke, Stun
Sniper Rifles: Dragunov SVG, M21, M40A3
SMG's: Mini-Uzi, MP5, Skorpion
Side-Arms: M9, M1991.45, USP.45
Assault Rifles: AK-47, G3, M4 Carbine, M16A4
LMG's: M60E4, M249 S.A.W., RPD
Create-a-Class: "Reach the rank of Private (rank 4) and you will unlock Create a Class. Here you can customize a class lead-out that fits your specific play-style. Create a Class is all about options - pick your primary weapons, side arms, grenades, attachments, weapon camouflages, and, maybe most importantly, Perks."
The default classes are:
Assault (M16A4/Grenade launcher, M9, Stopping Power, Extreme Conditioning, Frag/Stun Grenades)
Demolitions ( W1200, M9, RPG-7 x2, Sonic Boom, Extreme Conditioning, Frag/Smoke)
Heavy Gunner ( M249 S.A.W., USP.45, Stun x3, Juggernaut, Deep Impact, Frag)
Sniper (M40A3, M9, Flash x3, Stopping Power, Deep Impact, Frag)
Spec Ops(MP5, USP.45, C4 x2, Sonic Boom, Steady Aim, Frag/Flash)