I just read the two JLA: The Obsidian Age trade paperbacks, and can I say, that's just a great story. Especially read as a whole like that. Drama, mystery, time travel, cliffhangers ... I really think it stands up against some of Grant Morrision's JLA epics, second only to Rock of Ages, and that may be only because the art quality was more constant.
And I think it's too bad that Joe Kelly didn't stay on JLA longer, and get the opportunity, as he said in his afterward to Obsidian Age to tell more of the kind of JLA stories he wanted to tell. Because I liked the new, political JLA stories he began to tell, I'm looking forward to reading JLA: Rules of Engagement, and DC better hurry up with that JLA: Elite trade paperback! This year, eh?