According to GoWFans.com, at the end of Gears of War 2 there is a hidden message after the Epic credits roll from Adam Fenix. Does it foreshadow a third installment of the Gears franchise? Likely.
Below you’ll find the recorded audio and an explanation taken from the Gearspedia to decide for yourself:
“Adam Fenix is the father of Marcus Fenix, a C.O.G. soldier. He was a renowned military scientist at the East Barricade Academy, where he worked in a secret laboratory in his mansion’s basement. Apparently, his findings on whatever research he had been doing, were of importance. This is shown by the fact that Delta Squad returns to the mansion to retrieve the data, and they are pursued heavily by the Locust horde. It is later revealed that a portion of his findings had included a complete mapping of the underground caverns of the Locust tunnels. How he had completed these maps are still yet to be uncovered. It is possible that he obtained these maps by the use of the JACK series of robots, as he invented them and were originally used for mining purposes.”