That phrase is lifted from a pseudonymously written epistle offering an excuse for the destruction of the world to not yet have happened as promised. It amounts to the very same thing as the WT overlapping generation drivel. The writer of 2 Peter wasn't renouncing the destruction of the world but by indefinitely delaying the promised destruction for the sake of a vaguely defined greater good rendered the original promise effectively meaningless.
I believe slimboy was referring to what happens to the soul upon death. The end of our physical life, not the end of the world.