Time for another Keeper of Ulduar! In keeping with my previous posts, I will discuss them in the order that my guild defeated them.
Mimiron, Great Builder

Iron Gnomes- Not Just For Punting.
When you cruise on down into the Spark of Imagination- after battling your way through killer bomb bots, stealing the battletanks, the ‘Trash’, and taking a ride on the bullet train (which was VERY anti-climactic, IMO), you see this little guy- little in comparison to his fellow Keepers, anyways- busily hammering away at a miniature Flame Leviathan. He looks innocent enough… right?
Recommended healers for this fight: 6-7
Phase 1:

Because the first one wasn't bad enough...
The first thing Mimiron does- after berating you for breaking the XT-002- is hop into the Leviathan MK II ground assault vehicle. This thing has several different abilities:
Plasma Blast: an attack aimed at the tanks. Looks like a thin, red beam that does a considerable amount of damage. Tanks should be blowing cooldowns to survive this.
Napalm Shells: AoE attack targeted at ranged types. Has a range, so as long as you’re about 10 yards apart, the only one who should be affected by this is the target. Target will need immediate heals, as this is a fairly punishing attack.
Land Mines: Mimoron’s answer for not being able to Napalm the melee. He’ll toss out mines that will fall in a pattern, leaving sections open for escape. Not too much damage, but melee shouldn’t be hitting them, anyways.
Shock Blast: Similar to Stormcaller Brundir’s Overload ability. Melee need to run out of range or they will be one shot.
The basic strat here: Have a dedicated tank healer and 2 Napalm Shell healers- one on the right and one on the left. Raid damage is minimal in this fight as long as melee avoids the Land Mines and people don’t cluster up. Keep at least 2 ranged healers, just in case, and have the others assist the MT healer/ Napalm healers.
Phase 2:

BFG
In phase 2, good old Mimiron tucks the Leviathan MK II in the garage in favor of this bad boy- the VX-001 Anti- Personnel Assault Cannon. It pops out of a cylinder in the center of the room (NOTE: do not stand near it, it will throw you across the room.) Its abilities:
Rockets: It will shoot one of the rockets on its back up into the air. It will typically target ranged, but if there are no ranged to hit, it will drop it on the melee. Keep an eyeball out for a red and orange graphic on the ground and avoid it, thats where the rocket will hit.
Laser Barrage: This machine’s big attack. It will stop moving around and the big guns will start to ‘spin up’. He will then begin firing in a clockwise rotation. EVERYONE should move behind him to avoid the damage, as it will kill a tank.
The strat: Separate the ranged into three groups. Stick them in the large, pie shaped areas in the room with an AoE healer each (preferably). Melee should be right up on the VX-001 and staying on the wide, black strips that split the room into the pie shapes. All other healers should be with the melee.
Phase 3:

Proof that Blizzard's game designers are twisted.
In phase 3, Mimiron will stash the VX-001 in favor of this, which he calls his ‘magnificent Aerial Command Unit.’ Flying gnome head? Why not! This machine needs to be tanked by a ranged DPS type- my guild uses our resident warlock, Sasinko. Its abilities:
Plasma Ball: Its primary attack against the ranged tank. Fairly weak damage, but he does it often.
Bots: He will drop 3 different kinds of adds in this fight- Bomb Bots, which need to be soaked; Assault Bots, which need to be tanked and killed; and Trash Bots, which need to be destroyed. These bots drop Magnetic Cores, which are used to pull the flying gnome head down to the ground where it can be DPSed.
The strat: This is the easiest phase to heal, imo. Very little in the way of raid damage being taken. Put a dedicated healer on the ranged tank, the Bomb bot soaker, and the Assault bot tank. Have a melee drop the Magnetic Cores and burn him down. You’re aiming for less than 3 burn cycles on the head.
Phase 4:

You are NOT a real geek if you don't get the reference.
In phase 4, Mimiron is done playing nice, and he brings out all of his toys, which join up to create the V0-L7R-0N. This phase is the most fun- and most insane- of them all for healers. His abilities:
Shock Blast and Land Mines, as per Leviathan MK II.
Lazer Barrage and Rockets (x2 this time), as per VX-001.
Plasma Balls as per the Aerial Command Unit.
Hand Pulse: Only gained while V0-L7R-0N is all together. A short burst cone blast from his hands.
The strat: 2 tanks are needed- a Leviathan tank and a flying gnome head tank. Mimiron will use ALL OF THE ABILITIES LISTED, so your team needs to be on their toes. Rockets and Land Mines need to be avoided, when he spins up Laser Barrage, everyone needs to move behind the VX-001 portion, not the Leviathan MK II. Move out of Shock Blast. Have one dedicated healer on both of the tanks, and the rest on the raid. The 3 parts need to be DPSed down to about 100k health and then burned- please note that it is specifically to 100k health, and not a certain percentage, because each part has a different amount of health. Melee should concentrate on the Levathan MK II, while the ranged to DPS the head and middle. Feel free to swap DPS priority around as necessary. Defeat Mimiron’s machine. Get lewtz. Profit.
Well, thats it for today, folks! Happy hunting!