Another brief update based on the yesterday's findings: the PS3 Flash is quite accessible as the majority of it is mounted inside the PS3 as a filesystem (think PSP), and is able to be read/written.
A picture is below for a peek at a partial filelist. As you can see there are quite a few sprx's. These are encrypted of course, however they function quite the same as their PSP counterparts. For the majority of the PS3 OS's functions, there is a sprx that is tasked to do the job.
For the big chunk of interesting news: Every single scene release ever released for PS3 will not work without being patched.
Why? It is because backup PS3 images lack some data that we will call a key. On an original, when the disc is inserted, the PS3 reads the key, and it is used to decrypt any encrypted files on disc (the DISC layer of encryption). On a backup, the PS3 can not read this key so it will not be able to decrypt the file. Of course if a hardware mod surfaces this could change.
Making a patch is simple though, use an original disc, copy the file back off through the PS3 OS, and rebuild (we are currently using a modified BRDGen for our tinkering). This is being done via debug machine as we can both make and run our own code on it, but should retail consoles ever be able to run backups it may be possible on those too.
Furthermore, although more research needs to be done, there is no way to easily dump this key for endusers as it seems to be invisible to the Linux side of the PS3. It may be blocked by the Hypervisor, or is on an area of the disc that requires special lowlevel calls to read. Therefore, only those with a debug PS3 would be able to provide these keys from retail discs until either a PC app surfaces or retail PS3 console hack is found.
However, we suggest users continue dumping backups the same way, as they all should be able to be patched with the disc encryption stripped similar to how PS2 users patch DNAS data back into their images.
Finally there is full access to any game partition, with the ability to remove/change/add files and directories. One can replace game patch executables, hard-disk games themselves (and back them up). For the naysayers out there, this unit does run retail games quite fine, and is unlike the XBOX 360 development units since the PS3 units do hold all the proper decryption data for both debug and retail executables.
An interesting sidenote: the prototype controller's PS button lights up red while being charged!
You need a TEST/Debug PS3 to do it as detailed above... they can run unsigned/homebrew code, which is how the custom-made apps CJPC is using in all of the Dev updates are being ran.
If you have a TEST/Debug PS3, then you may want to do what was mentioned in the other thread here and message CJPC on IRC, get chatting with him, and perhaps get invited into the private PS3 Dev channel.
If you only have a retail PS3 console, you're SOL like the rest of us for now.