I agree, it likely won't be coming out until the 2nd week of October, mostly because they need to finish the couple of outstanding articles from September.
I still think that Striker and Defender are the most likely roles for the Barbarian. Whenever I think of Barbarian I think of hitting really hard with the biggest weapon you can find while toughing out blows that would kill an elephant.
It's possible that if the Druid is really going to be dual role that the Barbarian will as well and be a combo Defender/Striker. I don't think they'll be Controllers as I've heard some designers refer to melee and Controller not really working together at all. Swordmage is pretty much a Controller in melee already and they have a strong reason to have bursts and blasts(which are the hallmark of the Controller). I don't see any fluff reason for Barbarians to hit everyone in a Blast 3.
If we go by what was said in the preview books, then they are going very much for a Primal Fighter(of course, a lot of things from the preview books changed, so we can't entirely rely on that). If it is true, then I certainly see Striker being the most likely. They'll likely get something like "Lion Leap" where they charge an enemy, leap onto them and tear them apart. Or the ability to run really fast by summoning the spirit of the Cheetah or whatever. Mobility and damage seems like a Striker to me.
But then again, Barbarians have been associated with the Defender role in the past. They used to get d12s for hitpoints, get full BAB, and often stood on the front lines side by side with the Fighters and Paladins. If they decided to concentrate on this side of the Barbarian I could see their powers focusing more on getting the toughness of a Rhino and getting Damage Resistance, using the speed of animals to avoid blows, while still doing some good damage output. The only problem with this build that I can see is that I can't think of good fluff for a power that lets them Mark enemies using a Primal, Barbarian theme. Other than simply saying, "You are big, strong and dangerous, you use this power and your enemies recognize this and go after you first."
Still, I see them as a Hide wearing, Strength based Striker with a secondary stat in either Dex or Con. They will have more hitpoints or healing surges than most other Strikers and will have a couple more damage absorbing abilities(to be closer to a Defender than the other Strikers), but in exchange their abilities will apply less conditions and modifiers to the enemies. They will be slightly more "mindless" in that you will primarily be about absorbing and dealing damage without worrying about tripping, maneuvering, hindering, or other such tactics.