I've always wanted them to do more with him and I remember the story line in the animated series where Batgirl almost died and Jim found out she was Barbara after that he started a war with Batman and went so far as to bring Bane in on it. I've always wanted to see something like that done in the comics and while I don't think they'd do the same thing completely I'd like to see something similar done and I think something cool to see would be the Reaper redone and rebooted and for Jim to take up that mantle but for it to be a split personality type thing. By which I mean I think it would be good if something did happen to Barbara as Batgirl and her identity was outed and Jim just completely cut ties with Batman and shut him out 100% then time passes Barbara stays in a coma and someone starts killing off vigilantes and criminals in Gotham and it's a new Reaper.
I think this would be cool to see for Batman to have to deal with a dangerous serial killer who targets anybody with a super power or super identity while having to dodge the police. Then for the big twist to be that Jim's the killer and has developed a split personality I like this idea because it sort of preserves Jim as a character. I also think it would interesting to see something horrible happen to Barbara and for it to make Jim snap and I think he'd make a good enemy for Bruce especially because of how close he is to him.
I also like this idea because I'd like to see Jim antagonizing Batman throwing his hypocrisy in his face saying things like "You know you can say you don't kill but you have no problem tolerating murder if a Robin kills you just let it slide but hey it's fine so long as you don't kill right? Let's face it you have more blood on your hands than anyone else. How many people are dead or worse just because they were near or believed in you? How many times was Barbara in danger and you just lied to Jim's face?" I just like the idea of Jim going to the dark side and having an argument with Bruce like that.
I also would like to see Barbara's reaction if her dad went down a route like that and blamed Batman for everything bad that happened to her.