Its the first boss of Ulduar and surprisingly, it is a mount fight (your UI will be similar to maly 3rd phase when you are on the drakes). However, it is different from Maly since you will have different mounts to choose from.

 
1.1 Mount &amp; boss abilities
1.2 Strategy
   1.2.1 Siege Engine strategy
   1.2.2 Demolisher Strategy
   1.2.3 Chopper Strategy

So, generally here are the list of the each mount and their skill.
Each mount has a driver and a passenger. The driver and passenger have different skills they can use to hurt the boss.

1) Salvaged Siege Engine: 1 driver + 1 turret controller + 2 passengers 
Driver Skills:
1.Ram (40 energy) - 5400-6600 dmg + knockback (2850-3150 to buildings) 
2.Electroshock (38 energy) - 25 yard cone effect, spell interrupt, and 4 sec school lockout 
3.Steam Rush (40 energy) - charge + some dmg. 
Passenger Skills:
1.Anti-Air Rocket (10 energy) 0.25 sec 1000yrd - range rapid fire missile launcher 
2.Cannon (20 energy) - 10-70 yd range 

2)Salvaged Demolisher 1 driver + 2 passengers 
Driver Skills:
1.Hurl Boulder - 13.5k-16.5k dmg (10-70 yard variable range) similar ability to demolisher's in SotA or WG. Ignites tar. 
2.Hurl Pyrite Barrel - 27k-30k dmg (uses 5 pyrite) 
3.Ram - 8550-9450 dmg + knockback
4.Throw Passenger - Available only when passenger has loaded themselves into the catapult. Launches the passenger out of the catapult. (LOL  so a person will become the ammunition and will be launched  hahaha. as funny as it sounds, it is crucial that someone becomes the ammunition, top dps. and will be explained later)

Passenger Skills:
1.Cannon - Fires an explosive missile directly forward, detonating when it has travelled 50 yards, hitting any enemies within 10 yards.
2.Grab Crate - Use your hook and chain to grab the targeted crate. This allows you to pick up Liquid Pyrite off the ground, which reloads the demolisher.
3.Increased Speed - Injects liquid pyrite into the engines, increasing movement speed by 100%. Lasts 1 min.
4.Load into Catapult - Load yourself into the catapult arm, using yourself as ammunition. 

3)Salvaged Chopper 1 driver + 1 passenger
Driver Skills:
1.Sonic Horn (20 energy) - 3150-3850 to all enemy targets within 35 yards in a frontal cone. 
2. Tar - puts a 10 yard pool of tar down that slows enemies by 75% (lasts 45 sec). Tar can be ignited. 
3.Speed Boost (50 energy) - increases the vehicle's movement speed by 100% for 5 sec.


I know its alot of reading hehe.

Flame Leviathan
Skills:
1. Flame Jets - A 10-second channeled cast which does a massive AoE around the boss doing about 2000 damage per second. 
2. Battering Ram - Knocks back its target when in melee range, knocking the target back and applying a debuff which increases damage taken by 100% 
3. Gathering Speed - Slowly increases in movement speed for 5% per stack up to 20 stacks (100% speed increase) 
4. Missile Barrage - All machines and players not in one will take 700 damage every 1–2 seconds. 

1.2 Strategy:

2 tanks will be on the Salvaged Siege Engine + 1 passenger for each of the Engine (2)
2 will be on demolisher (top 2 melee dps will be the passengers and become an ammunition but can do dps before loading yourself as an ammunition)
2 will be on the chopper

The pull can start by any one.  There is no agro table for this boss as he will target one of two Siege Engine and run to them. Every 30 seconds he will target the other Siege Engine and move towards the new target.

1.2.1 Siege Engine strategy (read this if you are a tank spec going in Ulduar):
The tanks will be the drivers of the Siege engine, and their job is to basically kite the boss until DPS finishes him off.  The room we have to fight the boss will be in a shape of a square. 1 siege engine will be on one corner and other will be on the corner diagonal from the other. It does not matter who is on which corner. The Siege engine with aggro will kite the boss to the corner (hoping that takes 30 seconds so boss will target the other engine). while boss is chasing one engine, the other must be right behind him using the ram ability and electro shock when ever boss uses flame jets.  The driver who has agro will not do any dmg to the boss but simply run away, and the passenger of engine with agro will keep dpsing the boss with rockets. After 25 seconds for the first agro, the tank right behind the boss needs to be ready to run the heck away to his corner. When agro switch the engine that has agro must drive to his designated corner while the other engine who lost agro will stay behind the boss and dps using ram and electro shock.  For the tanks, its a rinse and repeat.  If Boss gets too close to you, use your speed skill to gtfo.

1.2.2 Demolisher Strategy 
We will need drivers for this as well. and 1 dps on each of the demolisher.  The job for the demolisher is to dps put out high dps. the driver needs to use hurl boulder and dps dps dps.  simple.  The reason why I put the highest melee dps on one of the passenger seat is because of the following skill that can make the boss deadly: Gathering Speed - Slowly increases in movement speed for 5% per stack up to 20 stacks (100% speed increase).  The boss has the ability called ram and it will do a good amount of dmg to the siege engine if it gets within melee range. The the buff stacks  and the only way to reset it is to have a passenger be loaded into the catapult and be thrown on top of the boss where they will dps down 1 of 4 turrets. Destroying the turret will allow for the one on top of the boss to reset his speed stack, stun him, and increase dmg taken by 50%.  Once the button is pressed (10 second channel). this is the time when the choppers, demolishers, and engine that is behind the boss must do the most dps as they can.  The drivers need to save the skill: Hurl Pyrite Barrel - 27k-30k dmg (uses 5 pyrite)  for when he is stunned.  I do not know how many stacks is optimal to call for a reset in his speed.  and we only have 4 resets because turrets do not respawn (i think). Other than that, passengers and driver for demolisher dps dps dps.

1.2.3 Chopper strategy (same model as the mechano-hog)
The main thing that choppers need to do is to set tar on the path of the boss to slow him down as much as possible.  The tar can be ignited by the demolisher's Hurl Boulder ability and will put a dot on the boss as long as he is standing on top of it. The second important job for the chopper is to swiftly pick up the melee dps (who upon pressing the button will be parachuted down to the ground or jump down idk really...) and take them near the demolisher where the dps can dismount and mount the passenger side of the demolisher.  the chopper has a dps ability called sonic horn,  and must be used to contribute to the dps and keeping tar down at all times.  Since we have 2 choppers, we will need to rotate dropping tar to reduce his speed. other than picking up dps from the ground and dropping tar, that is it for chopper.


So there you have it.   the tanks must be on the siege engine because the HP of the engine will determined by how geared the tanks are. 

I know its a lottt of reading and some people hate reading, but read up on this and i know we can 2 shot if not 1 shot this boss.  I am that confident about this strategy.

Here is a video link to show you a visual representation of how it will look like 
http://www.youtube.com/watch?v=GnsVDFMBFlA&amp;feature=related (in engine passenger point of view)


Tanks, notice how tank without agro is right behind the boss using ram and passenger doing dps the whole time with/without agro. 
Also notice the flame patch on the ground (tar + hurl boulder).
Choppers  notice how tar is dropped on this path at all times with hurl boulder on top to ignite and burn the ground.

tell me what you think, other than its too long and complicated  =-P