We should move these to 'scope' => 'header', or use 'defer' => TRUE as suggested by sun in #781994-7: Load mollom.js in scope 'footer'.
If we choose to use 'defer' => TRUE, we should attach behaviors when the script eventually finishes loading. This may happen after the HTML page itself has finished loading.
We could change the default parameters in drupal_js_defaults(), though perhaps this is too late for D7. I don't think 'defer' should default to true, because that introduces non-deterministic behaviour (depending on how soon the file finishes loading) that may confuse users and is hard to debug. Defaulting 'scope' to 'footer' may be a good idea, though.