To quote Rukari: "…the next character WILL NOT be teased."
He also said: "…you will more than likely have Gargos in your hands before you see his proper trailer."
Full post here: Stream before trailer, takes the hype away from trailer?
To sum it all up: Gargos’ trailer likely won’t come out until AFTER the 27th and there will NOT be a teaser for the next character. My assessment is that the next character is [CLASSIFIED] and they’re saving his official reveal for E3.