Passing arguments to drupal_get_form()
Just add $vars as second argument.

drupal_get_form('new_form', $vars);


and...

function new_form($form, &amp;$form_state, $vars) {
// ...


Quote from drupal_get_form()


  ... Any additional arguments are passed on to the functions called by drupal_get_form(), including the unique form constructor function. For example, the node_edit form requires that a node object is passed in here when it is called. These are available to implementations of hook_form_alter() and hook_form_FORM_ID_alter() as the array $form_state['build_info']['args'].