6 -> 7 upgrade instructions for hook_block inadequate

http://drupal.org/update/modules/6/7#remove_op

Only explanation is that $op is going and the only block example is:

/**
* Implementation of hook_block_list().
*/
function system_block_list() {
  // List of blocks
}

It should mention that there are these new hooks to implement:
hook_block_configure modules/block/block.api.php Configuration form for the block.
hook_block_info modules/block/block.api.php Define all blocks provided by the module.
hook_block_info_alter modules/block/block.api.php Act on blocks prior to rendering.
hook_block_save modules/block/block.api.php Save the configuration options.
hook_block_view modules/block/block.api.php Process the block when enabled in a region in order to view its contents.

and that some examples are available in http://api.drupal.org/api/drupal/modules--block--block.api.php/7/source