I agree that Ace is definitely not going to die. But the WG seems to be gearing up to start the execution. I was leaning more towards right as Ace is about to be executed, Luffy shows off some Haki and hits and Admiral to save Ace. But no, Ace will not die.
I believe that out of a fit of emotion over the imminent execution of Ace, Luffy will release a huge amount of Haki and end up punching one of the admirals. After that, he won't be able to hit them again. This could be the first self-realization of his own abilities. Otherwise, I don't see him...
