For those of us that created their account when they were 12 can finally rejoice with a free online ID change!
Your previous Online ID may remain visible to you and other players in some areas.
You may lose progress within games, including game saved data, leaderboard data, and progress towards trophies.
Parts of your game and applications may not function properly both online and offline.
You may lose access to content (including paid-for content) that you may have acquired for your games including content like add-ons and virtual currency.
You can revert back to any of your previous IDs by contacting PlayStation Support.