GLAUGUST, The Bad Doctor has given me a prescription for Eschatology, or, to give the proper prompt, "Post a timeline of the near, far and distant future of one of your precious pet settings".
In 6 Months, Zagyg the Fool, Baron of the swamp of Wug, will complete his ritual, sacrifice three godlings, and ascend to godhood. At the start of the game, he has captured the Archangel Temperance, and over the next 6 months will lure the Fairy known to mortals as the Yavtalathril, the Apple-Painter, and Adrammelech, Archdevil* of Unfair Taxes, into the vast dungeon he has constructed beneath Castle Greyhawk. He is unschooled in magic, yet taught in dreams by demons, and horrifically paranoid, never writing anything down (thus, his activities are unknown to Ioun). Zagyg will ascend as the god of Madness.
At this time, IREM, THE CITY OF PILLARS will start rise, annihilating the Abyss at a rate of one layer per week.
Further, the warlord Gruumsh will take into herself the vengeful spirits of the Orcs and the entire curse of the Fields of Blood, in an attempt to gain her godhood back. She will be put to death in her attempt by Gabriel the Fearless.
In 7 Months, Simeon Cuthbert the Stylite will ascend to godhood, seeing the chaos Zagyg causes. He was already well on his way: A faithful Peloran, he climbed onto a pillar in the wilderness of Omen nearly a hundred years ago to meditate on the nature of goodness. Ever since he has been fed by Birds with Food of the Deep Heavens. He has been slowly coming to the conclusion that Pelora is somehow wrong about what goodness is. This Zagyg upstart is just the straw that broke the camel's back. Saint Cuthbert will ascend as the god of Truth.
In 9 Months, Wey Jaz the Witch will succumb to the temptation of Zagyg, and sacrifice the entire population of Tyrnanokos, as well as herself, to the Well of Power. Wey Jaz will ascend as the goddess of Humanity**, and make war on the Four for their crimes. Zagyg, with the help of Avandros and Sehanine, will then search the world for the Seven Gems, which were the organs of Tharizdun, and call humanity** to descend into the abyss.
At this time, Hannibal Barca will destroy the City of Erathus, and put to death its immortal King. Further, Gabriel the Fearless will face the demon lord Graz'zt and defeat him. The annihilation of the Abyss will increase in speed to one layer every 3 days.
In A Year, Tharizdun will End the Dawn War. IREM, THE CITY OF PILLARS, that phantasmal place of colors in the dark, that island of lost things, that cavern of warm innocence that Tharizdun carved out of his own bones, will be restored by the Seven Gems into his True Body, and he will emerge into the world like a dream waking up. He has been watching the world, and he has found an answer. He will judge the gods for their rejection of him, and for imposing Death on humanity and disintegrating their souls. He will also judge human evil, for he has found that good is the answer.
However, all who descended to meet with him (or fight with him) in the abyss will receive his mercy, whether gods or mortals. Avandros and Sehanine have already done this. Ioun will do so at the slightest indication, for they loved He-Who-Was like a father, and the Raven Prince will be glad to stop doing that awful job. The Four (Pelora, Ashmadeva, Erathus, Melor) will take a lot of convincing, blinded as they are by self-righteousness and guilt.
Tharizdun will end death forever, and bring humanity with him into the Astral Sea, where he will speak with the Eldest and reveal why the stars are going out. Humanity will live there forever, with the World remade and nestled in a crèche of the Deep Heavens, until at last humanity outgrows the World.
In A Millenia, humanity will outshine the stars.
Some of these things are set in stone. Some of these things players can change.
*An Archdevil is a godling, offspring of one of the Lords of Hell and another god, in this case Ashmadeva and Erathus
**Properly, this should read Immanity, a term that encompasses all the mortal races and quite a few immortal ones.

