Deathwing will in all likelyhood be the final raid of the Xpac so dont expect him any time soon. At the moment we are all dealing with the after effects of the Cataclysm.

Deathwing is probably NOT the final boss. I'd expect Ragnaros, then Deathwing, then... whomever "hired" Deathwing. Because if the quests make one thing clear, he's not the Dude In Ultimate Control.

So someone hired Deathwing? Okay, that just made things really interesting. As a major Warcraft nerd that causes me to start thinking of someone or someones (a group of people) who would actually do that. I really hope that's true because now I just may go back and finish the quests in areas I skipped. :)

Think "old gods."

No, nobody *hired* Deathwing.

Long story semi-short:
Neltharion used to be the Aspect to watch over the earth with the other Aspects, was corrupted by the Old Gods, forged the Dragon Soul with pieces of each Aspects power in it, killed a lot of the Blue Dragonflight (which is ironic as Malygos was his closest of friends within the dragons), got the Soul stolen from him, couldnt find it for 10,000 yrs till the Second War. He manipulated people left and right, making the Dragonmaw Clan kidnap Alexstrasza, took a vacation in Outland for a bit (creating the Netherwing, and his mate Sintharia creating the Twilight Dragons), came back to Azeroth, Demon Soul destroyed, fled to Deepholm where he brooded and planned for years and years, and just now came back tearing a hole through the planes.

Ergo, he has a long history of corruption and evil.

@Phort The long history of evil and corruption is largely due to his being manipulated by the Old Gods. Have you quested all the way through Twilight Highlands yet? The quests make it pretty clear that we're not dealing just with a naughty Neltharion doing what he does best. Deathwing's literally been transformed into something else by the power the Old Gods gave him, much like Queen Azshara, and he's definitely working for them. There's no real question that Deathwing's a puppet, not the puppetmaster.

A quest in Twilight Highlands implies that Deathwing isn't the DRAGONS ARE THE BEST AND I'M THE BESTEST guy he used to be. He ends up yelling this: "Then witness my new gifts, bestowed by this world's true masters!"

After all, it's kinda hard to rule a planet and take Alexstrasza and Ysera as your sex slaves when the Twilight's Hammer want to blow it up and the Old Gods either want to blow it up or control it themselves.

As he's now a flunky, presumably of the same Old Gods he worked against in the War of the Ancients, the only way I can see him likely as the last boss is if Cataclysm is setting up the Old Gods for another expansion.

As a big of a Warcraft nerd as I am (and I'm pretty damn proud of that fact too LOL >

It could be done in a similar way to WOTLK with Ulduar released before ICC pitting you against an old god/minions, before the guy on the front cover of the game.

I hope anyway Deathwing is the final boss since most of the zones relate to him doing SOMETHING