That scene was AMAZING, I laughed so hard. It really spotlights what YJ is doing so well as a show, and that is building a real depth of character in the animated DCU that, in my opinion, eclipses JL/U. The JL shows covered lots of ground and opened the door for tons of characters to get their first animated treatment, but YJ is getting a lot more into the characters, how they relate to each other, and how they develop. John Stewart has only said a few words, and Hal and Guy haven't spoken at all, but in that one little scene we learn a great deal about how the GLs in this universe relate, and thankfully it's pretty much what we would expect. Kind of interesting though, given Guy's extensive League history (longer than John's, really), that in this world he's never been a member. Still dig the take on his costume.
Here we also have confirmation that it's just them - given what we've seen so far, I think it's safe to assume that Kyle Rayner is in High School art class somewhere. But given the tweaks they've given to characters like Zatanna, it would be awesome if they found a way to bring him in over the course of the series, even if it was just a one time deal.
The voice actor is Kevin Michael Richardson, and he is incredibly prolific. He's Kilowog and has done several additional voices on GL:TAS, Martian Manhunter and Nabu/Dr. Fate on Young Justice, Bulkhead on TF: Prime, and Panthro in Thundercats. Honestly, I was a little disappointed in his casting as Kilowog because I feel like he's a little overexposed for the range that he has (he does deep and resonating... and that's about it). I liked Michale Madsen in First Flight a little more (even though he didn't get to do anything) and was surprised by how Henry Rollins did in Emerald Knights. That said, his voice seems pretty well suited for how they're writing the character, and I love that he gets to play partner in this series.