iTunes Match, Apple's answer to the "online music locker" service, has just entered beta according to an email sent out to members of the Developer Program. iTunes Match will store users' music libraries in iCloud, allowing anywhere/anytime access to the entire library from any device.
iTunes Match is now available to US-based developers, and subscribers will receive iTunes Match service both during the beta period and an additional three months beyond the beta period for free.
Concurrent with the iTunes Match beta is a new beta version of iTunes 10.5, beta 6.1. Developers must download this newest beta of iTunes in order to enable iTunes Match. Apple encourages developers to continue maintaining backups of their iTunes libraries,