jstnryan

When I originally wrote the hack (as seen in the link above) it was intended only as an example of how someone could accomplish this functionality, not a best-case solution.

To my knowledge, there are STILL no appropriate hooks into the image_resize( … ) function, as of WP 3.0, so you’ll have to continue to apply my hack manually.

For anyone curious, in the mean time, I’ve resorted to manually editing all of the appropriate files in /wp-admin/ adding the following to the div tag:
onclick="jQuery('div#message').css('display','none');"

Playing off what fltseng wrote I came up with this:

/wp-includes/media.php line #363:

if ( !$suffix )
{
  switch ($max_w) {
    case (intval(get_option('large_size_w'))):
      $suffix = 'large';
      break;
    case (intval(get_option('medium_size_w'))):
      $suffix = 'medium';
      break;
    case (intval(get_option('thumbnail_size_w'))):
      $suffix = 'thumbnail';
      break;
    default:
      $suffix = 'other';
  }
}

It’s a hack, unfortunately, instead of a plugin, but it works for me so far.