In May 2nd's release, EnvO's "terrestrial biome" hierarchy has been consolidated and terms which subsume several potential biome classes (e.g. "Mediterranean forests, woodlands, and shrub biome") have been split for better semantic resolution. Previous biome classes have been obsoleted and "replaced_by" or "consider" relations added between obsolete terms and new classes where possible. Some definitions are still being formulated and will be added soon along with synonyms.
Additionally, an "anthropogenic biome" class has been created and will be populated in the near future.
As always, feedback, input, and suggestions are welcome and are best submitted via EnvO's Google Code issue tracker.