1st generation 60gb PS3 with firmware 3.15
 
WORKING:
Bioshock 2 
Resistance 2
Red Faction: Guerrilla
Street Fighter IV
Little Big Planet
Call of Duty 4
God of War Collection
Uncharted 2
Uncharted 1 
Infamous
Genji
Folklore
Resistance
Grand Theft Auto 4
Metal Gear Solid 4 
Borderlands  
FIFA 09
TES IV Oblivion
TES IV Oblivion GOTY
Fallout 3 GOTY 
Ratchet & Clank: a Crack in Time 
**Bionic Commando Rearmed **  (Demo Only)

  
NOT WORKING (8001050F ERROR):  
Darksiders
Killzone 2
Dante's Inferno
Demon's Souls
Heavy Rain
Dragon Age Origins
Modern Warfare 2 
Final Fantasy XIII
White Knight Chronicles  
Batman Arkham Asylum (works for a short time then errors out)
All downloaded PS1 games 
Downloaded DLC (i.e. General Knoxx, etc.......)
 
** NOTE:  All downloaded games that you can upgrade to the full version from a demo revert back to the demo version even if you have already bought the full version (i.e. just like Bionic Commando Rearmed listed above as well as others noted below by Tepid Shark)

What does your list look like?

White Knight Chronicles does not work, Imma play some GTA 4, Thanks for this.

Thanks guys for posting.  I updated the list.

Haven't had the same problem on my Slim PS3 (250gb) and the only game that I played after hearing about  the issue was Disgaea 3 which works fine.

Lucky for me I was playing Okami before shit hit the fan.

Uh, I guess the Yakuza 3 demo works, if that counts.

Every blu-ray game (not downloadable games) without trophy support works, that's what everybody is saying in other forums. I only tested with MGS4, though, and it worked.
 Oh, and I don't know if it will help the list that much, but... Final Fantasy XIII doesn't work also.

Hey guys I found another strange symptom.  
I restored my PS3 to default settings and restarted it.  Then I changed the date and time from 31 Dec 99 to 28 Feb 10 at 9:47 PM (when it was actually that day and that time).  
The strange part is I just now turned on the PS3 again and it has the date at 28 Feb 10 at 9:52 PM.   When in fact it is actually 1 March 10 at 12:44 AM here!  WTF this is weird.
It only accounts for date and time when the system is turned on......as soon as you turn the system off it pauses the date and time until you turn it back on again.

Games that you can upgrade to the full version directly from a demo revert back to the demo version even if you have already bought the full version. These include Wipeout HD, Bejeweled 2, Peggle, Marvel Vs. Capcom 2, and there are probably others as well.

Bioshock 2 worked when I played it this morning, can somone verify this.

"Hey guys I found another strange symptom.   I restored my PS3 to default settings and restarted it.  Then I changed the date and time from 31 Dec 99 to 28 Feb 10 at 9:47 PM (when it was actually that day and that time).   The strange part is I just now turned on the PS3 again and it has the date at 28 Feb 10 at 9:52 PM.   When in fact it is actually 1 March 10 at 12:44 AM here!  WTF this is weird. It only account for date and time when the system is turned on......as soon as you turn the system off it pauses the date and time. "

A guy Tribular over on IGN.com posted this:
 
"For those of you technically/mechanically inclined to do so... 

Open up your ps3 and reset the internal clock by disconnecting and then reconnecting. This should change your internal clock back to the manufacture date....This is not a PSN problem. People are reporting in multiple forums by doing this procedure, their Playstation problems are resolved...

This is obviously a system hardware problem and I am not sure there will be a fixable solution for download. In theory, after 24 hours the internal date should move into "2000" and the system may work...However,I do not except a quick fix form Sony any time soon....I hope I am wrong."
 
The guy did not post a source so it seems kind of shady.  However, I wonder if this really fixes the problem?  I have no clue on how to reset the internal clock though because he does not even tell you what to disconnect/reconnect.  I assume he is talking about the battery?  Does anyone here have a source that can confirm this as a fix?  I'm playing it safe and waiting for Sony to give us a fix.

I have the same problem with my PS3. I have the Asian (40GB) version, HDD upgraded to 250GB . I've got the same error code, same trophy and sign in error messages. The only difference is the date., it was set to 1/1/2000 rather that the 12/31/1999 the others are getting. Some say it was a "leap-year" "Y2K-like hardware issue," well maybe but I don't think so. I find it odd that this problem coincides with the some page updates both on the US & Asia Playstation sites (particularly the USN PSN trophy page). 
 
I'm 11 hrs ahead of US EST (I'm in Asia). I left my system downloading (The Tester) overnight, woke up, watched the videos, turned it off then I left the house at 6:30am. I came back at around 2pm, turned on my system and the startup was noticeably longer than usual, the PS3 logo took a while to showup. I tried Darksiders on, it made me quit because of the trophy error (both online & offline), checked my trophy list, Darksiders isn't there. Tried to sign in, it gave the sign in error message. I saw the incorrect time & date at this time. Now here's another odd thing, upon checking my Facebook page, it shows some recent trophies I've obtained from Darksiders as a status update posted at 9:00am. Remember I wasn't home at that time. I suppose they'd sent some subtle updates "covertly" overnight on to the affected PS3s, that, I don't really mind as long as a simple system software update will be able to fix it.

When did this update happen? I finished Heavy Rain only 3 days ago on my first generation 60gb PS3. That sucks that some games aren't working, I hope they fix it soon.

Might not wanna say " Works perfect" We do not know if you get a trophy wile the server is down that you will keep it when it comes back up. 

" @THE_END: Borderlands (offline) works, but no DLC. "

 I noticed that the games that aren't working are games that came out within the past year whereas mostly everything else that works was released in 08 or 07.

So far I have only tried to play Heavy Rain to no avail. I was playing Aliens versus Predator all day yesterday and it was fine. But I haven't tried it since I first encountered the error code when I tried to boot up Heavy Rain.

" @Red12b: hey...do you have a old fatty? "

Batman AA doesn't work apparently:  

Thanks guys the list has been update!

Dante's Inferno doesn't work.

You might want to add that any downloaded games won't work either. Even PS1 games.

I have a 40 GB PS3 from Summer 2008.  
 
Works:  
inFamous (Trophies are ALL gone) 
MGS4 (doesn't have trophies) 
Uncharted (My trophies for this game never worked anyway)
Genji (No trophies) 
Folklore (No trophies) 
Resistance (No trophies) 
 
Doesn't work: 
Demon's Souls 
 
So... the only game I actually want to play doesn't work.

Updated.

so apparently anything with trophies is ok, and most single-player based games (inFamous, Borderlands) work but with no trophies.

Nice list duder. On my launch 60GB:

Resistance 2
Red Faction: Guerrilla
Street Fighter IV (without DLC)
Little Big Planet (without DLC)
and CoD4
 
All work fine (offline, obviously)
 
Killzone 2 isn't working (Trophy error -2147416817 though...)
 
Everything else on your list is accurate for me, except for the fact that my MW2 works fine offline; no idea why that would be though...

LATEST UPDATE:
http://blog.us.playstation.com/2010/03/latest-info-on-playstation-network-status/
 

Everything I have tried to play works but it doesn't matter anyway. If you have a "fat" PS3 and it's working, like mine, you probably still shouldn't be turning it on, per Sony's advice. I mean, why take the risk. It's one day.

" Hey guys I found another strange symptom.   I restored my PS3 to default settings and restarted it.  Then I changed the date and time from 31 Dec 99 to 28 Feb 10 at 9:47 PM (when it was actually that day and that time).   The strange part is I just now turned on the PS3 again and it has the date at 28 Feb 10 at 9:52 PM.   When in fact it is actually 1 March 10 at 12:44 AM here!  WTF this is weird. It only accounts for date and time when the system is turned on......as soon as you turn the system off it pauses the date and time until you turn it back on again. "

updated.  I think those others are downloadable games.