Theme node body with a template file in the feature

gistfile1.php

<?php

/**
* Implementation of hook_theme().
* DRUPAL WONT SEE THIS HOOK UNTIL YOU CLEAR YOUR CACHE
*/


//Create myfeature-node-body.tpl.php in your feature and use $node to theme the node body

function myfeature_theme() {
  return array(
    'myfeature-node-body' => array(
      'template' => 'myfeature-node-body',
      'arguments' => array('node' => null),
    ),
  );
}

/**
 * Implementation of hook_nodeapi().
 */
function myfeature_nodeapi(&$node, $op, $a3, $a4) {
  if ($node->type == 'mytype') {
    switch($op) {
      case 'view':
        $node->content['body'] = array(
          '#value' => theme('myfeature-node-body', $node),
          '#weight' => 10,
        );
        break;
      case 'load':
        //add any extra data your template needs to $node here
        break;
    }
  }
}