As a part of the 1.6 redesign, the Biome Islands are going to be revamped for the 1.6.2 version of HEE (which also means that old worlds will not be completely compatible, chunk borders in places of islands may be visible and Biome Compass will only show correct places for new islands).

Two key concepts are planned - content variations, and random deviations.

Content variations will each have a different set of content, objectives for the player and general look to the island. There is one content variation per island, the target for 1.6.2 is to have 3 variations for each biome.

Random deviations might be compatible with multiple content variations. They are random switches that affect specific features generated on the island, such as "tall trees" switch that gives all trees a chance to generate taller than usual.

Moving to private tracker.