AppleInsider reports that QuickLook will be making its way to Finder icons themselves in Mac OS X 10.6 Snow Leopard.
The detail which was revealed to the site by a person familiar with the future Mac OS X release. The site writes that hovering the mouse pointer over an audio file in Snow Leopard's Finder will trigger a triangular 'play' button to appear on the icon. Hitting the button will trigger the audio to play without opening any applications.
The process also works for video files.
AppleInsider reports that other files such as Pages, Keynote and Number files also cause the Finder to show navigation buttons on its icon to allow navigation of the document.