Playstation underground is in the midst of being destroyed. PSN IDs will be merging with Playstation.com. At a later time users will also be incorporated into the Playstation blog. That ultimately means the end of Playstation Underground. This means a move of about 14 million users to the new network.
This is a new attempt to create a better playstation experience with the use of a streamlined social networking system.
Existing users still may link their Playstation underground accounts to PSN IDs.
Sad day for the long established Playstation Underground. Now we wait for this new and improved version to awaken, hopefully it works well.