8 Biggest Things To Come Out Of Doomsday Clock #1
2. It's Implied That Manhattan Has Gone To New Earth
While Rorschach's identity was always going to be a hot topic of conversation before Doomsday Clock's release, the whereabouts of Doctor Manhattan was a lingering question Johns and Frank would have to address eventually.
The answer, so it would seem, is that Manhattan is on New Earth - DC's mainstream universe where Batman, Superman and all the other heroes reside in. More interesting, however, is that the book switches to Superman's perspective once Veidt ends his speech on tracing the blue demigod's whereabouts. Not only does this imply that Manhattan has made the switch to DC's most famous locale, it also infers that the two will collide in some sort of way, as is evidenced by Supes' newly acquired insomnia.
It's the only connection between the two worlds so far, but there's plenty to make of Manhattan's transition to the mainstream DCU.
It certainly seems as though Johns is alluding to the man in blue being responsible for the universe's recent (and indeed maligned) reboots, and if he has a bone to pick with the Man of Steel in particular, then Doomsday Clock's story could be hotting up more quickly than we all initially expected.