A NEW mob isn't a planned mob. The so called "Red Dragon" had been removed and the enderdragon took it's skin. Pigmen are only there to hold up Zombie pigmen.
Also, If a mob is new, that means no varients of it exists in minecraft.
Oh? Did Mojang tell you specifically what they meant by 'new'? That is your opinion of 'new'. And only the minecraftwiki states that they are planned, and the wiki is not necessarily correct in that regard. What may be 'new' to you, may be old and long-due for Mojang.
I've never heard of that, then again I don't follow jens and nathan THAT closely. It would really suck if they did add those though, I for one, was against the idea of Dragons, I play minecraft to get away from those crap games, but in the end (no pun) I really like the ender dragons.
Actually it was Notch that promised adding red dragons, and pigmen skins/models have been in the game since back in the Notch days (like Giants).
I really hope it's not pigmen. If the new mob IS pigmen, and they were to spawn in Jungles as pigmen villages, the only way I could see that being appropriate was if they were hostile to the player, since we already have peaceful villagers.