This thread is about Half life 2: Episode 3. Not Half life 3.
Gameinformer revealed Half Life 3 Not Half life 2: Episode 3
Smart assery aside, *spoiler alert* Immediatly after Eli informed you that he was GOING to inform you about G-Man (Anyone that payed attention will know that G-man is a community given name, so that whole gman is gordan freeman is bullshit, Just had to get that out of my systen) Dog hears something and runs off, After Eli killed dog jumps in and saves you in the nick of time, time seeming to be something Gman understands a great deal about. Personally I think gman wanted Eli killed specifically because he was going to inform you about him.
So, in Half life 3 you will most likely uncover a great deal more about Gman and his employers I sincerly doubt that the gman is evil, in any way, I don't think it gets that black and white, (the same way gordan isn't really a hero, To him he really is the right man in the wrong place) But he definitly has an agenda, But his and his employers are almost certainly not the same.
Further thoughts: Apart from gman, I'm guessing we'll figure out what happened to Barney in episode 2, Maybe even Corporal Shepherd, I hear rumors about him, but I don't think so because hes a gear box character I believe.