As promised, Sony has begun the full restoration of its PlayStation Network services in all regions with the exception of Japan, Hong Kong, and South Korea.

The company made the announcement in a blog post last night, saying that customers once again have access to a huge lineup of downloadable games, demos, add-on content, themes, avatars and videos from the PlayStation Store, while Plus subscribers should see new full game trials and other freebies.

The promised content as part of the Welcome Back offer to customers is not yet live, though. Sony says it is currently in the final stages of testing and will make the content available to download soon.

Sony cut off its PlayStation Network and Qriocity service on April 20, a day after detecting what it called a "very sophisticated" intrusion that compromised the personal data of over 100 million users. A partial restoration began two weeks ago – on May 15, 2011 in the Americas and Europe/PAL territories, followed by Asian countries and regions on May 28, 2011 – with online game play, account management, friend lists, and chat functionality.

The company has estimated it will need to set aside around $171 million to cover the costs of the investigation, cleanup and insurance needed to resolve the issue, as well as implementing updates to the network to prevent further occurrences. That doesn't include legal expenses from ongoing lawsuits, however, nor additional losses if identify theft or credit card fraud are detected as a result of the PSN security breach.

Sony has been in the crosshairs of hackers for a while now and it seems its problems may not yet over. Hacker group LulzSec has been promising attacks on Sony for the past few days, posting to its Twitter account that it is engaged in an operation dubbed 'Sownage,' shorthand for Sony Ownage, calling it the "beginning of the end" for the company.