Re: Batman should die in the next film!
It wouldn't merely be to be "edgy and different". If that was the only reason then I'd consider that to be a poor excuse to do that. It would be to bookend Nolan/Bale's run and open the door wide open for a new take on the franchise. Hopefully one that would enable Batman to fit in more with stuff like the other DC heroes or employ more of his more fantastical villains.
2015 will not only see the MCU beat the HP franchise for the #1 WW spot but it will also see Marvel Studios pass Pixar in terms of WW grosses($8.585 billion). Marvel Studios/MCU avg. annual profit: $621m(there ain't none higher. HP was the closest runner up with $541m when it was active).