In Beta1, probably the best way to accomplish this would be to use EntityColumn.GetEntityColumns for the entity type. Entity columns are auto-generated into the factory classes for the entity properties defined in the CSDL.
In Beta2, we now have an EntityMetadataStore, and a much improved EntityMetadata class, which has getters for most of the interesting metadata you'd want to retrieve.
Beta2 should be available by the end of this week. (Hopefully I haven't jinxed it!)