oh, i think the docs are plain wrong (or rather: completely outdated). see for example http://cmf.liip.ch/en/admin/bundle/block/simpleblock/list

so we can say the BlockBundle provides handling of the blocks and a few commonly used standard blocks including editing them. i would drop the sandbox here then, as everything cmf is demoed in the sandbox. can you also update the symfony-cmf-docs please?