Yeah, this is a new/reformatted hack and or plugin for WordPress. A little while ago I released a ported hack to give you a live preview for your comments. It has been picked up by a lot of sites, I am pretty happy about it really.
The devs have not gotten around to adding back in any kind of preview for new posts to WP(with good reason, they are pounding away at some good features.) a user on the forums wondered if my hack could implemented for the post/edit system. Good question; so I took up the challenge and while I was at it converted the hack to a plugin to make it more user friendly. So now I have real time preview in my comments box and the admin interface, pretty spiffy.
If you would like to tackle adding this to your WP installation, you can find the fully commented plugin file over here.
This is Sillyness Spelled Wrong Intentionally. Going strong for 11 years, 19 hours and 36 minutes