Singleplayer
http://youtu.be/2zw8SmsovJc
http://youtu.be/9UwOrl036_A
Multiplayer
http://youtu.be/aPu7-LtLKmU
http://youtu.be/XhBjBy5OOFY
http://youtu.be/m8S_eEv_A5k
Tech Demo
http://youtu.be/8pNOxynC1Dc
Multiplayer on consoles features 16 vs. 16 matches (PC gets 32 vs. 32). EA does provide dedicated servers, essentially eliminating lag and host advantage which can be found in other FPS titles. The class system has been revamped:
Assault
The Assault class carries a primary weapon consisting of an assault rifle — like the M4 and AK-47 — and is now merged with the medic class — the Assault class can now heal and revive teammates. It can also function as a more offensive class with ability to swap out the revive kit for a grenade launcher.
Support
The Support class returns to its role it had in Battlefield 2, with its main purpose to provide heavy fire from a Light Machine Gun (like an M249 SAW), and resupply teammates with ammunition. In Battlefield 3, the Support class is broadened with the ability top use lighter weapons and assault rifles like the M4, with several attachments, including a powerful flashlight which has the ability to blind enemies in dark places.
Engineer
The Engineer class in Battlefield 3 is very similar to the class in Bad Company 2: its primary role is to engage tanks and armored vehicles with an array of rocket launchers such as the RPG-7 and the AT4, or use anti tank mines. The primary weapon is a carbine rifle, with a variety of unlocks available, ranging from shotguns to sub machine guns.
Recon
The Recon class carries a sniper rifle for long range engagement, but for Battlefield 3, the Recon class has a more active role as well. The Recon also has the ability to call in artillery strikes (expected unlock). Furthermore, the Recon can equip C4 explosives to blow up enemy vehicles or map objectives.
Source
Known for its emphasis on vehicles in multiplayer, Battlefield 3 thus far has confirmed:
- ATV
- Jeep
- Light tank
- Heavy tank
- Support helicopter
- Attack helicopter
- Jet fighter
Based on the most recent installment (Battlefield: Bad Company 2) we can also expect:
- Jet ski
- Motorboat
- Anti-air tanks
The weapons list is even more extensive, but I'll go ahead and say that there's no short supply in variation for all four classes. With the role of Medic being merged with the Assault class, we won't have to worry about overpowered medics who carry light machine guns, health packs, and reviving defibrillators. It's hard to tell how the balance is, but even BFBC2 was pretty balanced despite medics being top-tier. Gametypes such as rush and team deathmatch have been confirmed, and conquest will most likely make its return.
To bring more hype to the table, EA is dropping over $100 million for advertising purposes. The Frostbite 2 game engine is already being hailed as the most beautiful graphics technology to date. I myself have played Crysis 2, and I would readily agree that the Frostbite 2 edges out the Cry Engine 3 technology. Here's an example of what the game looks like if you take close look:
Good times.
