This is starting to feel like sharks smelling blood more than any actual concerted effort to discredit or undermine Sony. The Anonymous DDoS attacks were actual attacks intended to harass Sony. The PSN attack and the SOE attack seemed more just a blatant criminal acts in an attempt to steal customer info for personal gains. Then there was the web-server that was being used to host a phishing scam, again, a criminal action. Now we have this latest attack on Sony's music servers in Greece and appears to be more the hackers showing off that they could do it. The disparity of these attacks seem like they are all of different groups with different objectives, with the only truly potent attack being the PSN breach.
Sony's security has proven to be severely lacking, so now all the sharks are swimming in to take their nibbles of the carcass. If I were Sony, I would definitely be instituting a new policy to completely overhaul the security of all servers(better intrusion monitoring, transaction journaling, stronger firewalls, better use of strong encryption and access controls), take off-line any servers that are deprecated in functionality(like the website that was co-opted for the phishing scam), re-architecture the databases such they are less exposed to the internet, re-architecture access to the databases to more tightly secure communications between the database and authorized client systems, and change policy to ensure that all software is constantly kept up-to-date. These changes would be applied company-wide to all server systems that must interface with the internet or store company critical data, such as customer records.
Honestly, unless Sony improves its security everywhere at every level, it can just expect more of the same. Just like with wild animals, once the scent of blood is in the air, the crazed frenzy continues until they(the wild animals) are completely exhausted of energy or there is just nothing left of the corpse. (Hackers, bullies, gamers, politicians, corporate executives, internet assholes, terrorists, you name it; doesn't matter. Human beings are not necessarily so far removed from our more bestial beginnings. We still have a long way to evolve, yet.)