Back in November, a leaked email from Apple to record label representatives indicated that 90 second song previews were in the works for the iTunes Music Store. Today, without much fanfare, the Cupertino company has begun to roll out the extended song previews to its digital music store. The site’s current top albums all have received the upgrade treatment, although, most songs still have the original 30 second previews. Apple has yet to issue a press release formally announcing the feature.