In the trailer without talking, when you first see the Thunderkittens, they are running. Then you see Cheeatra with her staff. Then you see Panthro running, holding a sword. Then you see Tygra with his whip. Then you see Snarf.
That’s not Panthro. Panthro has a Blue-ish face and No beard. http://geek-news.mtv.com/wp-content/uploads/2011/03/kevin_michael_richardson_as_panthro-300x136.jpg
http://www.thundercatsnow.com/wp-content/uploads/2011/03/17.jpg And as you can see the guy with the sword is brown and has quite a beard.
Panthro hasn’t been in either of the trailers.
I think it is Panthro. He’s smack dab in the middle of individual team shots in the promo. First the Thunderkittens. Then Cheetara. Then this guy. Then Tygra. Then Snarf. It makes no sense for this guy to be anyone other than Panthro for that reason alone. There are no other scenes, it goes from Kittens to Cheetara to him to Tygra to Snarf.
I get the impression that Lion-O is going to team up quickly with Tygra, Cheetara and the kittens and Panthro later on. But it makes a lot of sense that Panthro was there when the attack happened. It’s possible that in that battle is what gives Panthro the scar over his eye that we see in the official pictures that have been released with him in it. It’s also possible that he shaved his beard different after that, so that his beard was fuller in the battle and later on when Lion-O meets up with him, he’s changed the style of his beard.
As for the brown color, that could be attributed to by lighting.
Just my therory.
Panthro is not in the trailer because he’s not in Thundera. He’s off exploring Third Earth.
That is not him. It doesn’t even look like him.
even the beard and the coloring aside (and lighting would not make blue look that light shade of brown) Panthro is a LOT bulkier with muscle than that guy.
Hmm… I suppose time will tell. 
I’m curious about the green armor Tygra is wearing in the promotional picture. I haven’t seen him in that in either trailer and I’m starting to wonder if he will wear that at all in the show or if it was just some kind of conceptual art?
I think that armor is something Tygra will get from Panthro once they meet him. I also noticed that the whip he has in that promo art has a more complex handle than the one seen in the trailer.
I agree. I think the clothes we have seen Tygra wearing so far are his “Royal Thunderian” ones, and when they leave Thundera, he will use the green one.
As for the bolowhip, I read in an interview posted here somewhere that they did have redesigned it.
I really like that theory. Makes sense. In the trailer, we see the Thunderians fighting the Mutants with bows and arrows, I imagine they also had swords, so very Lord of the Rings. But then the Mutants come with a far advanced technology that the Thunderians don’t have and are thus forced to evacuate their lands. Makes sense to me that Lion-O and comapany would then flee with no technological advancements, they meet Panthro who knows technology and team up with him. He builds the Thundertank, perhaps even the Tower of Omens if not he may work to fortify it. And he probably builds armor and advance weaponry for the ThunderCats. So Tygra’s armor as well as the gun in his hand in that picture. I wonder if then we’ll be seeing the other ThunderCats armored up because it wouldn’t make sense to me why only Tygra. Hard to say.
I was just noticing something about Tygra’s armor. It kinda looks like the same material as those enormous machines used in the Mutant invasion. I wonder if that armor was made from one of those machines that the ThunderCats brought down. Just a thought.
Tygra actually goes through three costume changes. He’s wearing an armored version of his royal suit in the outside invasion shots in the Wondercon promo. Perhaps he decided that the only way to fight invading hordes of mutants with high tech weaponry was to snatch a gun and increase the level of his armor?