http://www.arma2.com/weaponry_en.html
Added during GDC. Their blurb says 73 weapons but I haven't counted them myself.
Pistols
Colt M1911A1, Beretta M9, Beretta M9 SD, Makarov PM, Makarov SD
Assault Rifles
AK-107, AK-107 GP25, AK-107 GP25 PSO, AK-107 PSO, AK-74, AK-74 GP25, AKS-74 Kobra, AKS-74U, AKS-74UN Kobra, AKM, AKS, M16A2, M16A2 M203, M16A4, M16A4 RCO, M16A4 M203, M16A4 M203 RCO, M4A1, M4A1 QDS, M4A1 QDS CAMO, M4A1 M203 RCO, M4A1 CCO, M4A1 M203 Holo, M4A1 M203 Holo SD, M4A1 M203 SOPMOD SD CAMO, G36, G36C, G36C SD, G36K, XM8, XM8 M320, XM8 Marksman, XM8 Compact, XM8 SAW
Machine Guns
M240, M249 SAW, Mk48 Mod 0, PKM, RPK-74
Sniper Rifles
CZ 550, DMR, KSVK, M107, M24, Mk12 SPR, SVD Dragunov
Special Purpose Weapons
MP5, MP5SD6, PP-19 Bizon, VSS Vintorez
Shotguns
Benelli M1014, Saiga 12K
AT/AA Launchers
FGM-148 Javelin, FIM-92F Stinger, Igla 9K38, M136, RPG-7V, RPG-18 Mukha, SMAW, Strela-2 9K32
Mounted Weapons
AGS-30, DShKM, Kord, Browning M2, MK-19, ZU-23
Static Launchers
Igla AA Pod, AT-9K115 Metis-M, Stinger AA Pod, SPG-9, TOW
Artillery
Podnos 2B14, M252 Mortar, D-30 Howitzer, M119-A1 Howitzer
I hope they do the same for the vehicles.
Added during GDC. Their blurb says 73 weapons but I haven't counted them myself.
Pistols
Colt M1911A1, Beretta M9, Beretta M9 SD, Makarov PM, Makarov SD
Assault Rifles
AK-107, AK-107 GP25, AK-107 GP25 PSO, AK-107 PSO, AK-74, AK-74 GP25, AKS-74 Kobra, AKS-74U, AKS-74UN Kobra, AKM, AKS, M16A2, M16A2 M203, M16A4, M16A4 RCO, M16A4 M203, M16A4 M203 RCO, M4A1, M4A1 QDS, M4A1 QDS CAMO, M4A1 M203 RCO, M4A1 CCO, M4A1 M203 Holo, M4A1 M203 Holo SD, M4A1 M203 SOPMOD SD CAMO, G36, G36C, G36C SD, G36K, XM8, XM8 M320, XM8 Marksman, XM8 Compact, XM8 SAW
Machine Guns
M240, M249 SAW, Mk48 Mod 0, PKM, RPK-74
Sniper Rifles
CZ 550, DMR, KSVK, M107, M24, Mk12 SPR, SVD Dragunov
Special Purpose Weapons
MP5, MP5SD6, PP-19 Bizon, VSS Vintorez
Shotguns
Benelli M1014, Saiga 12K
AT/AA Launchers
FGM-148 Javelin, FIM-92F Stinger, Igla 9K38, M136, RPG-7V, RPG-18 Mukha, SMAW, Strela-2 9K32
Mounted Weapons
AGS-30, DShKM, Kord, Browning M2, MK-19, ZU-23
Static Launchers
Igla AA Pod, AT-9K115 Metis-M, Stinger AA Pod, SPG-9, TOW
Artillery
Podnos 2B14, M252 Mortar, D-30 Howitzer, M119-A1 Howitzer
I hope they do the same for the vehicles.