How do I add a link to an operations dropdown menu in views?
Add the following to your hook_menu in your module to add an operation to the dropdown pulldown of commerce orders. 

$items['admin/commerce/orders/%commerce_order/&lt;your operation&gt;'] = array(
    'title' =&gt; 'Your Title',
    'page callback' =&gt; 'your_callback_for_the_operation',
    'page arguments' =&gt; array(3),
    'access callback' =&gt; 'your_access_callback',
    'access arguments' =&gt; array(3),
    'type' =&gt; MENU_LOCAL_TASK,
    'weight' =&gt; 30,
    'context' =&gt; MENU_CONTEXT_INLINE,
);