updated 08:30 pm EST, Wed December 14, 2011
European countries also seeing the option
Apple appears to be quietly rolling out iTunes Match to a number of countries this evening, judging from reports of users who now see the option to sign up available under their iTunes account information pages. Pricing for the service has been revealed to be $28 in Canada, £22 (approximately $34) in Great Britain, and €25 (approximately $32.50) in Europe and equivalently-priced elsewhere.
The company has not yet begun promoting the change internationally in its overseas iTunes Stores, leading some to believe that the rollout is in error or at least slightly premature. The service may be accepting signups (and generates confirmation e-mails indicating that payment has been accepted), but MacRumors quotes a UK Twitter report saying that the service does not yet seem to be operational yet. It is working, however, in Brazil, where the iTunes Store only just recently opened for music purchases.
The iTunes Match service offers, for a modest yearly fee, to make high-quality 256kbps AAC copies of a user's music files available to them on any device they own or authorize for libraries up to 25,000 songs. When active, iTunes Match scans a user's library and identifies songs that iTunes also has. Users have the option of replacing their own copies (which may have come from any source) with an iTunes Plus version, or leaving the local library as-is.
The practical upshot is that users no longer need to try and load large libraries of music into their mobile devices, which are often very space-limited. Songs not already on the device are listed and can be instantly downloaded free of charge. All artwork and user meta-data (even custom meta-data) is preserved. In the case of the user owning a song iTunes Match can't identify, the song will be uploaded to the user's iCloud account (no penalty of space is taken for this) so that the unmatched song is also available.
Apple's method avoids users having to upload the entire library of music, unlike competing services from Google and Amazon, and offers a flat-rate yearly fee rather than pricing based on the size of the library. As a result, a typical user's entire library of music can generally be available to their mobile devices and other authorized computers within an hour or two.
Canadian version of the iTunes Match signup page