5 Great Comics That Will NEVER Happen Again
1. JLA/Avengers
It is a truth universally acknowledged that comic book companies are actually just big fussy babies. It doesn't matter how good an idea it may be, if it promotes the other guy, DC or Marvel refuses to do it. So there's basically zero hope of something as awesome as JLA/Avengers ever happening again.
Oh sure, there were plenty of crossovers between DC and Marvel before this, most famously a crossover between Superman and Spider-Man that tried to convince people that the two took place in the same universe. But since Marvel and DC are now playing with the big boys in the movie industry, and DC is kinda getting thrashed, it's unlikely that either side feels like playing ball.
Maybe this will change in the future once they get less confrontational CEOs. We certainly hope so, considering that JLA/Avengers is considered canon to both, it would definitely be nice to get some resolution to the lingering plot threads from that storyline. But until then, one can only hope.