Something that would be quite handy is to obtain some kind of context as to where the old form code was found. For example:

Drupal 4.6 - project_settings, line 133:
form_select(t('Reply-to address on e-mail notifications'), 'project_reply_to', variable_get('project_reply_to', ''), $items);

This is not a huge deal in simple forms with only a hook_form and hook_settings or so, but some modules get very complex and define many forms, making it difficult to search. This would also allow you to check "at a glance" to see how many functions you have to convert before the module is complete.