(Yes, that is the worst butchering of the line ever, but I couldn't work out how not to be epically spoilery about the rationale for his decision to leave DC and quite writing GL—I don't know how common knowledge it is, and the quickest scan of the IO9 GL tag didn't reveal anything). The following paragraph, however, will contain what I've heard about the upcoming plotline.
Killing John Stewart? Ah, dear. I guess this is freedom? If you have the ability to not have to write the storylines you don't like/disapprove of, you should indeed exercise it, I figure, and leave the gig to someone who's less negative about it.
Me? I'm incredibly negative about the idea. I'm not sure what DC's precise slaughter motives are, but none of them even make me want to check out the comics in the store. They just do not seem to promise anything interesting, just emotions I don't want to feel.
Has DC mastered punishing people who then come back for more? And I just missed the memo? Also, really, I do think that if you are killing a minority in your title, at least make sure you thought twice about it, because it does not have the same impact as killing a non-minority. It won't, for a while.