Many members of the DGML have been dissatisfied with the conventional Dreamlands. They find them too green and pleasant, too far removed from the grim horror that infiltrates the Delta Green world. For the most part, they have quietly avoided the issue by not discussing what happens when the characters sleep, or perhaps not letting the characters sleep at all. Some of the DGML members don't do anything quietly, however, and have re-imagined the Dreamlands in ways that are more fitting to the dark post-modern world.
A different take, which depicts the Dreamlands as the living embodiment of the collective unconsciousness. In this view, the Dreamlands are being constantly altered by every person that falls asleep. Each area of the world would have its own Dreamland, which would reflect the secret longings and needs of the people who live and sleep there.
The whole idea is a compelling approach that opens up room for doing all sorts of bizarre "alternate history" kinds of situations. The "pocket dreamland" angle allows for things to be more twisted and surreal than you might otherwise be able to get away with.
Dreams in black
The Heralds of Hypnos, Mirror World, Carcosa, Good Times and Tsan-Chan ideas below were all contributed to the DGML by the Man in Black.
How about a timetravel/YOG-SOTHOTH sliders sort of adventure where all of history has been altered in the 1920's by investigator failures. A 1000 year reich where Edward Chandler was elected president of the US in 1930, there was no great depression in America, and the Axis powers won WWII with the USA as an Axis Power. A world rapidly cracking under the Seeds of Azathoth, with an atmosphere being drained away by a gate into an interstellar nebulae. A gate created by a rocket launched in 1928 by cultists in Shanghai.
In the 1990's the world has rapidly seen the rise of Mythos entities of all sorts and Majestic-12 is an illegal conspiracy working with the Mi-Go to stall the ENDTIMES. Delta Green is merged with the Karotechia as the Secret Police of a Global Fascist State which serves the Mythos, with Stephen Alzis as World Dictator.
Many of the events discussed in Bill Timmins' ENDTIMES website could happen much earlier in this timeline. Along with fun stuff like the Gulf of Mississippi (from the New Madrid Quake of 1987), the Californian Archipelago, and the Amazonian Ocean. Antarctica could be thawing in this time and the Collapse of the Ross Ice Shelf would have raised Ocean levels drastically.
A campaign taking place entirely in Carcosa. This has problems due to the total lack of conflict in that surreal city. This problem is being solved by your Man in Black. Watch out for my New Carcosa background. Characters like the Pumpers who, equipped with skull-plumbed cranial spigots, use elaborate chemical apparatus to interface with the plumbing of Carcosa by pumping all manner of occult fluids into their heads. Kinda like netrunners in Cyberpunk, only with hallucinations and high weirdness. Secret Societies like the Saffron Order, dedicated to defacing all the Yellow Signs in the city. Clockwork characters, surreal steampunk cybernetics, and occasional glimpses of undulant tentacle armed folk surrounding a mysterious figure in Yellow.
A parallel universe where Delta Green was not disbanded in 1970 and the Mythos activity is much more contained than in standard CoC. The adventure here is when researchers start going nuts… too much information, and the price of success.
Why not a campaign set three thousand years hence? How to do it? Easy. "You have been chosen to defend the Earth Realm against the evil forces of OutWorld in a tournament held once every 500 years. A tournament called : MORTAL KOMBAT!" Make sure you play really loud techno music so everyone has to shout things like "Fatality!", "Flawless Victory!", and "Oooh! That's Gotta Hurt!" to be understood :)