Tanking: 2 tanks are needed on both 10 and 25-man. The OT should taunt Saurfang when the current tank gets Rune of Blood. Beware of multi-target abilities (Glyphed Maul, Heart Strike, Consecration) when the adds are spawning, since you don’t want them sticking to you.

Healing: You want to go into this fight with the minimum number of healers possible, especially for heroic mode. Because of the Mark of the Fallen Champion mechanic a Paladin healer’s Beacon of Light is godly on this fight, and Paladins also bring another Hand of Protection.
The tank will require 2 healers on 25-man, and then one person should be assigned to prioritising the Boiling Blood.
When the Marks come up, the first ones should be assigned to Paladins as Beacon targets, and then a single healer should focus on each subsequent Mark. Shaman are good choices, especially on melee, since they can chain off the target to heal the tanks as well.

Buffs: Amplify Magic is safe here, since everything is Physical damage.
Mortal Strike and equivalents can help if Saurfang is getting heals off from Rune of Blood.
Frost traps and other slowing effects are valuable to help control the Blood Beasts.
Hand of Protection, Divine Shield and Ice Block can be very useful in slowing the rate at which Saurfang gains Blood Power.
Finally, make sure you have a Mortal Strike, Aimed Shot or equivalent on Saurfang to reduce any heals he gets off from hitting the tank with Rune of Blood. Unless you’re really quick, he will heal this way.

Key Debuffs: Mark of the Fallen Champion, Boiling Blood, Rune of Blood.

Bloodlust: At 20-30% (during the Frenzy, preferring execute range) depending on how long the fight will go on for after the BL is popped. Alternatively, and more usefully for heroic, at the very beginning of the fight when you get the most uninterrupted DPS time in a stretch. This will also reduce the number of marks active by the time you reach the Frenzy, making healing significantly easier.

The main gimmick with the Saurfang fight is that every time he (or his Blood Beasts) inflict damage with a special ability he gains Blood Power. When this reaches 100 he will cast Mark of the Fallen Champion on a random player, causing them to take ~5,000 physical damage every time Saurfang attacks the tank (but this does not stack Blood Power any more. If the Marked person dies (bear in mind that the debuff doesn’t fade for the duration of the fight, and persists through death making battle ressing worse than useless) Saurfang heals for 5% of his health.
The key to the whole fight is to delay the Marks as long as possible by preventing him or his Blood Beasts doing any damage.
The stacks appear as his “energy bar”. Obvious to some people, not to me as a healer 🙂

Two tanks are required, because approximately every 30s Saurfang will debuff his tank with Rune of Blood. Any hits on the tank with Rune of Blood will also leech 7,000 health from the target and heal Saurfang for 10 times that much, and add Blood Power. Make sure you have a Mortal Strike debuff on him at all times, especially if your tanks tend to take a hit each time.

The ranged need to take care with positioning, spreading out at least 12 yards to prevent Blood Nova hitting more than one player at a time. This can be planned out ahead of time, since generally the ranged will be static throughout the fight. Healers can stand in mêlée range to make more room, although they must watch their thread when Blood Beasts are spawning.

Besides Blood Nova, Saurfang will be casting Boiling Blood on random players (1 on 10-man, 3 on 25-man) which will need to be healed through. This will stack Blood Power with every tick, so if you can clear it using Ice Block, Hand of Protection or Divine Shield this should be done immediately. Because it is a physical debuff, Cloak of Shadows does not work.
(NB: This used to only stack Blood Power if it dealt damage, meaning that a Disc Priest’s PW:S could negate one or even multiple ticks, but this was fixed and now doesn’t work)

The final tricky aspect of the fight is the Blood Beasts. Saurfang will summon 2 of these in 10-man, 5 in 25-man, at his feet and they have a buff (Resistant Skin) which decreases damage taken from AoE and multitarget effects (Cleave, Multishot etc) by 95%, and from diseases by 70%.
Because you don’t want to be melee’d by them to avoid giving Saurfang 3 Blood Power per hit (and because they hit like trucks on cloth), ranged should all break off from the boss and nuke them down fast, running away if they get targeted, while melee should remain on the boss. Chains of Ice, Frost Traps, Frost Shocks, Earthbind Totems and Hamstrings are really, really helpful. Army of the Dead is a really, spectacularly bad idea because they will taunt the Blood Beasts and get hit a lot, stacking Blood Power sky-high in seconds.

At 30% he will Frenzy, increasing his attack speed by 30%. This changes nothing about the strategy, and DPS must be disciplined and continue to kill the Blood Beasts throughout this phase.

Bonus tip: Saurfang will reset if he reaches your gunship. Unfortunately his Blood Beasts won’t, so your tanks may need to help you wipe!

Heroic

• Saurfang has approximately 13 million health as opposed to his 9 million in normal mode.
• Saurfang hits a little harder normally.
• Every stack of Blood Power Saurfang has currently increases his damage done by 1% each stack. When this gets over 75 it begins to hurt the tanks a lot, requiring cooldowns.
• Hitting the tank with Rune of Blood heals Saurfang for 20 times the damage, rather than 10 times. Mortal Strike is much more important.
• A death of a Marked player heals for 20% of Saurfang’s health, compared to 5% on normal mode.
• Blood Beasts move a lot faster.
• Blood Beasts gain Scent Of Blood, meaning they deal 300% more damage (practically a one-shot) and reduce nearby player movement speed by 80%. This means they need to be reliably snared: they simply cannot be allowed to get near people.
• A Blood Beast hitting a raid member adds 20 Blood Power to Saurfang.

The big difference strategy-wise is managing the Blood Beasts. They must be controlled and the ranged they target must use every trick they have to get away, since they give Saurfang so much Blood Power and they are so dangerous if they hit a player. Since they come up in predictable positions, and are marked by boss mods, CC/Slows and DPS should be assigned to marks, similarly to the way Val’kyr are assigned on the Lich King fight.
Melee DPS absolutely must be careful of their AoE, cleave and splash damage so they do not aggro the Beasts under any circumstances.

On 10-man, because healing is at a premium, care will be needed to maximise healing throughput once Marks are up. A Holy Paladin will effectively negate the first Mark with Beacon of Light, and makes the fight a lot easier. If you have a Resto Shaman it is possible for the Marked player to move into mêlée range and the Shaman can Chain heal off them onto the tanks. Priests can switch to Binding Heal if they get Marked. The aim is to use multi-target heals as effectively as possible.

Blood Power Summary Table

These are from memory. It’s a real pain tracking down real numbers for this, and since it’s not a buff it’s not reflected in the combat logs either. I’ll update this when I have more information or verification.