The First Week
When you download Emperium on the 27th you will have access to all the content except for the Sundered Plains level 40 Zone and the raid. The main reason the max level content will be staggered is to give room to the other systems to breath for a bit before immediately invalidating them with Epic quality items.
This means the max level zone and raid will become available May 4th. The update will go out at 12pm PDT that day. You will then be able to select a new option "The Sundered Plains" from that point on a new zone will be unlocked to the east of Deathstroke Marsh
Devlogs Going forward
Dev Blogs are probably the best way I have to continuously update the community on the game's development as well as preview upcoming things. Because of this I will try to keep at least 1 every month. This also lines up with how I'm planning actual updates to the game.
This should be the last update from me before release, a new dev log should be out 2 weeks post launch to give insight on content release for the future and the general philosophy with patches