I'm relieved to report that
I've successfully rescued all data (even protected) from my YLOD Ceramic White 40GB PS3.
It only cost me my time, tears, and about $35.
Thank you all for the resources discussed on this thread, they were invaluable. My PS3 yploded suddenly this past thursday without any warning signs. Bitterness and spilt milk aside, I became most concerned with recovering my data. It's a crappy feeling when you realize that there is no way to get at it without the very same console. So, I set out to revive the very same machine.
I followed the information presented here and a variety of sources, hoping for a repair that would at least let me perform a backup. I was afraid of all the reports citing the uncertainty on how long the machine would remain alive post repair.
It was intimidating, but not too bad in retrospect. If you do this, make sure you're well organized. I managed to bring it back, but was far from done. The first thing I did was copy all my allowed saves to a USB stick. I performed a full USB HDD backup afterwards. Knowing most of it was now safe, I made preparations for a full ethernet data transfer. I picked up a new slim PS3 to receive the data.
Then, trouble hit again. I had to update the newly revived PS3 to firmware 3.15, where it gave an error midway through the process, getting stuck in an endless loop. A little research prompted me to open it back up and make sure everything was connected properly. I knew that everything was working properly, but it hit me that I hadn't used the blu-ray drive since the repair. The ribbon connector for it is also very delicate in how it mates to the drive. The update was a success after I re-did this connection.
Everything was going fine until the data transfer started hitting an error, too. It turns out that any problematic or corrupted files will kill the transfer without giving you a reason. In my case, it turned out to be a corrupted Heavy Rain dynamic theme. If you run into a similar situation, remember your themes. I triple checked everything while forgetting this, since it sits in a separate menu.
After a long, long weekend, I've got everything back up in order. DLC, saves, copy protected saves. What a horrible experience.
My Ceramic White YLOD PS3 is repaired with Arctic Silver Ceramique compound and flux. I decided to get a new one because I didn't like the idea of not knowing if / when this might happen again. Apparently though, some people are ok with this idea, and multiple repairs. I will be sending it to ebay soon, where it'll hopefully find a good home.
I'm a little bit sad I couldn't replace it with a similar unit. That Lightning PS3 is far too expensive.