I understand the need to protect IPs from theft, prevent cheaters from ruining online gaming experiences and keep especially malicious hackers from remotely damaging other consoles or servers. Security is an absolute necessity in the online world, but when it comes to security in the online world it has to be done server-side, not client. It's why player-characters are stored on MMO servers and not the host machine, for example; when the user has access to things that ought not be tampered with, they will find a way to tamper with them.
If all goes extremely well, the new PS3s will function for the vast majority of users in a virtually indistinguishable manner from the current and prior models and will just provide a new puzzle for console hackers to tinker with. And let's not kid ourselves, they WILL find a way to hack the machine in some form or another.
If all does not go so smoothly, and I must confess that my faith in Sony is less than absolute for the current console generation, then there are a host of problems that can surface. For instance, compatibility with: games that were designed on older SKUs; servers that were designed to communicate with older SKUs; older consoles connecting to newer consoles online. At best in this scenario the only result is some lag or other less-than-perfect online experiences such as machines not being properly validated and rejected from online play or even resulting in unjustly banned accounts. At worst, these odd combinations could open up new exploits in servers and consoles that did not exist before that could be a playground for malicious hackers.
Hopefully Sony is taking these types of scenarios, and many more that I wouldn't even know to come up with, into consideration and are successfully addressing any problems that might arise. It all feels like an unnecessary effort though. The hackable consoles will still exist and it's only a matter of time before the new ones get hacked as well. Why not just leave things where they are? That way they know what to look for and effective ways to counter it. With this new console, they've potentially doubled their security workload.
Maybe I'm being too much of a Negative Nancy on this. I certainly hope so and would love to see Sony be successful in their efforts to curb online cheating and malicious hacking, but time always tells, so we'll see what happens once the new console is released.