I've been banging the drum for a Hal/John book for years now. These two characters have a long history with each other that's so ripe with potential. They're friends and brothers, but there's a tension between them that's always been there. And yet these two guys undeniably respect each other. John is the only GL that has consistently been shown as capable of beating Hal, who is rightfully considered the best of the best within the Corps. With all the questioning of authority that Hal Jordan is known for, the only leaders he's ever shown deference to were Superman and John, who began as the most anti-authority GL.
Like I said, there's a lot of potential there. I'm shocked that DC hasn't tried to capitalize on it yet. Hopefully, the new editorial direction will rectify this.
Currently, Jess, John, and Hal are DC's three most prominent and popular GLs. Rather than segregating them in different books, I'd like DC to stick them together and see how they bounce off each other.