It's too early to tell if this is just a bug, glitch, or if someone actually hacked Sony's PlayStation Home server to change the message for all PS3's, however, what is confirmed thus far is that numerous people have experienced the same issue.
That being said, lorello1978 shared a video on YouTube which states the following, via rough translation:
I turned on the PS3, I started Home, I did the upgrade required. Restarted the console, at one point turning in Home in my house, I noticed a terrible slowdown, as to seem a lag of the modem.
Not understanding why and thinking: "I like the fiber optic connection and I have a 320GB inside ... why !?!?"
I open the console window in Home and I go to see the messages and news, to see what improvements have brought the new upgrade...
Then I read these things a little reassuring that you see in the video. Someone knows what happens? I am the only one? More PlayStation 3 News...
doubtful as the compromise in code was exploited on the SCE server side and not the ps3 side.
I just thought that maybe that if someone has hacked Home and gotten it to run on the PS3 then other things may be possible but I guess I could be pushing it...I just want a 'Hello World'