LulzSec tweeted:

We’re working on another Sony operation. We’ve condensed all our excited tweets into this one: this is the beginning of the end for Sony.

Update 2: I was reading further in the tweets of LulzSec and I found that they are planning to begin Phase 1 within the next day:

(Sony + Ownage) Phase 1 will begin within the next day. We may have a pre-game show for you folks though. Stay tuned.

So this means they are apparently working on another operation against Sony. Well, I am not sure whether this is the same group behind the PSN hack but I really do hope Sony will take every security measure possible to protect its fame and it’s users.