As expected, EA has released the the Battlefield Vietnam 1.2 patch, adding a ton of new content to the game. For those with 1.1 installed already there is an incremental upgrade. For server files go here. Here's what's new map and vehicle wise.

NEW CONTENT AND FEATURES

3 new maps in Patch 1.2:
-- Operation Cedar Falls is a new map that introduces tunnels to BFV. Minimap changes when inside tunnels, and teammate icons only appear if they are on the minimap the player is currently viewing (ie above ground or tunnels). Tunnel flags appear in the minimap as vertical flags, differentiating them from the regular horizontal flag.
-- Saigon 1968. Based during the Tet Offensive, the NVA have tunneled into the Saigon Sewer system in an effort to overtake the Presidential Palace.
-- Fall of Saigon. It's spring 1975, and the NVA are moving quickly to attack Saigon as the USA is finishing the final evacuations from Vietnam.

8 vehicles are new in Patch 1.2:
-- The A1 Skyraider in 2 versions; one for anti-infantry (MGs and napalm), and the other for anti-vehicle attacks (bombs and missiles).
-- The Ontos is a new USA tank that can fire 1 round from it's 6 cannon sequentially, or it can empty all 6 at once.
-- The BRDM Malyutka Complex is an NVA amphibious vehicle that fires wire-guided missiles. Once fired, the player camera is attached to the missile. The control is similar to an airplane. Right-clicking will detonate the missile.
-- Quad 0.50 MG is a static machine gun emplacement with 4 powerful cannons. A 360 degree rotation and a thick bullet shield make it a great option for clearing the skies of enemy targets.
-- T-72 is a heavy NVA tank. The driver fires tank shells with primary fire, and shoots a machine gun as secondary fire. The gunner fires the canopy machine gun with primary fire, and shoots out smoke grenades with secondary fire.
-- AC-47 Gunship. Heavy transport/gunship with coaxial chain guns out the left side. The pilot can drop bombs with primary fire.
-- M35A1 Nancy. A flatbed truck with a Quad 0.50 MG mounted in the back, an M60 facing to the front, and a couple armed passengers for good measure.
-- BM21 Troop Transport. A BM21 truck with armed passenger positions filling the back.

The Battlefield Vietnam website notes that updated mod tools will be available soon.