This time, for real. In an email to developers, obtained by Macworld, Apple says that the iCloud libraries of testers will be erased this weekend in preparation for iTunes Match's public launch.
According to the email, libraries will be erased at 10 a.m. Pacific on Saturday, November 12. Beta testers are asked to disable the feature on all of their devices prior to that point. Though tracks on computers shouldn't be affected, Apple advises that users keep a backup of their music and don't delete tracks from their Macs and PCs.
This isn't the first time Apple has deleted iTunes Match libraries, but the note that this is to "prepare for the launch of iTunes Match" is new, and suggests that service will go live shortly thereafter.
At its iPhone event in early October, Apple set the end of the month as its goal for launching iTunes Match, but that deadline came and went without any further announcement from the company. While options for iTunes Match have appeared on iOS devices and the Apple TV, setting up the $25-per-year service requires the as-yet unreleased iTunes 10.5.1 running on a Mac or PC.
Once available to the public, iTunes Match will allow users to upload their iTunes libraries into the cloud, then listen to that music on all of their devices. Apple originally announced iTunes Match last June at its Worldwide Developer Conference as a part of its iCloud online service.