So this is a hardware-problem, right?

Can you fix a hardware problem via software-update? I actually don't know. This is no trolling, but a serious question.

Otherwise, people might have to send their PS3s in for repair. That would be the worst case scenario.

As a software developer I can tell you that there are tons of hardware problems that can be "worked around" by software.

In this case, if the problem really is the non-existent 29th of February, the work around will probably be to assume 29th of Feb = 1st of March in the years when this bug happens, 1st of March = 2nd of March etc.

This is not always possible though, it depends on how bad the hardware problem is. If the internal clock gets totally borked, the only way to get correct dates may be to fix the hardware or reset it by removing the battery and then updating the clock manually or something...

There's also the separate problem of what corruption this may cause on people who did turn on their PS3s today. That could be a whole other mess, and more complicated actually (if it affects the DRM, etc.).

CECHG03 = not working, cant sign in to PSN anyway...BBCiPlayer is working...and browser...FIFA 10...will not work

As far as I understood it this is what happened:

Its the system clock it has NOTHING to do with the PSN. The Anti piracy measures start to work because the system Clock is messed up ( You cant influence the system clock its useless to change the date or time. 

if you download stuff (full games,Dlc) or have certain games installed the system noticed the time when you did this but if the system clock shows a date prior the install the system thinks that you changed the clock somehow to hack the system and nothing will work. Also it messes up your trophies because the time you won them and the time the system says it is dont adds up so they just vanish but they are saved anyway on sonys server so they arent away.

This problem has  nothing to do with beeing Online in fact it is even helpful if you were connected during the incident. Because your system was synced with the PSN Clock so nothing happened. If you switch off your system after midnight everything should work fine. Also I think that the PS3s system clock works internaly with GMT time so all systems work with the same time and the system cant be messed up. The problem actually occurs to a total random time depending on the time zone you live in.

my ps3 is rarely connected to the internet, and it wasn't when I started it up today, and it hadn't been for a week, and the date is messed up,
oh well maybe sony can change the ad to it only does nothing

yes with what problem's they are stating , it seem's the fault lies in the Bios chip on the onboard mother board of the PS3 which mean's yes it can because the Bio's chip is flash updatable like you would any PC the Bios of the ps3 has it's own wait state that is remembered even when the system is shut off due to a battery . one of the people that had a PS3 that yload on him he had to open up the PS3 which of course void's the warranty. but he had to remove the battery that keep's the motherboard's Bios software state. when he put it back together he is able to go online and go into PSN and play game's, what we do not know since he has not switched off the PS3 of logged off if the Bug would infact effect his PS3 also, but it look's to me like it would because, even if you still have the bug your PS3 can still visit other web sites.

the internal clock setting's that are in the PS3's bios are vital to some software in order to run.

so yes it can be fixed by Firmware, but depending on your PS3's bios that may take time IF it's not the same Bios chip all across.

or infact that the Bios chip may have a 24 hour corrective measure for time states as shown in some other electronic's.

Have any countries rolled over to the next day already? I cannot remember the timezones for China or AU.

in 7 hours or so

I think what many do not know how vital that internal clock in the Bios is for the overall well being of your unit..
how something you would not think would be this Vital is. it's one of those thing's that make it because of system state's are very important on how your system stores data when powered on or off.

I remember one of the best well known exploit's to get around the shareware time limit was to change your clock! it's not so common anymore but that was just one little thing that could indeed change how software and your hardware interact. just by changing that one little thing in your PC.

It's 2:45 in Sydney.

0:45 in Tokyo, and 23:45 in China

However there are people saying that PS3s failed according to GMT time, so the timezones may not matter.