According to the Codex, it should only be used for inline script tag(s) in the head. I've been using add_action('admin_print_scripts-{my-hook}'
for injecting .js and add_action('admin_print_styles-{my-hook}'
for .css without any problems. I use wp_register_script() & wp_enqueue_script() (and the corresponding *_style() ) to enqueue them.
A "view source" shows
<link rel='stylesheet' href=[...] />
and
<script type='text/javascript' src=[...] ></script>
being inserted into the <head> correctly.
Does anyone know any reason not to use them this way, other than a poorly-written Codex description that says not to?