Just noticed automated comment preview on the newspaper group...

I just noticed that groups.drupal.org has enabled an automatic preview for comments. Now a window is generated automatically to present a preview of a poster's comment, eliminating the need to click the preview button in order to see the comment.

I kinda like this feature. Does anyone know what module does this? And whether it could also be applied to content types, rather than just comments? And whether there are irritating side-effects to doing this?