The Lost Sinner's crime was her attempt to light the First Flame, which would imply that it has gone out, and that humanity has been in the Age of Dark for some time now. Either that, or the Flame is on the verge of death. This is compatible with either ending of the first Dark Souls, since the flame would eventually go out even with a "Chosen Undead" to rekindle it. If that is true, then the Abyss has not consumed everything yet. The Abyss covenant might shed some light on that.
Any thoughts on who the individual gods might be? One of the lore descriptions suggested that their names might have changed over time, just as those of the kingdoms have.