Equivelant of node_type_load() for entity bundles
You can use entity_get_property_info() for example

var_dump(entity_get_property_info('node'));


Bundles are a keyed array within the result and they contain a keyed array of the fields and their settings.

Other information about the bundles other than field properties, such as menu callback etc, can be obtained using entity_get_info() where the bundles as keyed array within the result contains other non-field info.