I know that setting $t = get_t() is common in hook_requirements, but I've never seen a double-dollar sign in front of $t before. This looks accidental.
Diff between the 1.0 version and the 1.1 version:
$requirements['plupload'] = array(
- 'title' => t('Plupload library'),
- 'value' => t('Unknown'),
+ 'title' => $$t('Plupload library'),
+ 'value' => $$t('Unknown'),
Is this double dollar sign intentional?