Hmm this actually sounds quiet possible. Now im no expert but I'm guessing this is how it might work.
1) on PS3 power on, instruction are loaded from on die rom, and that loads bootldr.
2) in place of the original bootldr, there would be the bootloader happily masked as bootldr. And in said bootldr a bootmii like menu is presented. One of the options will be to boot normally and that option is in turn an instance of the real bootldr, therefore boot system normally.
Now this is completely a thought and is not in anyway showing how it would exactly work or even if it would work. Just an idea people......lol.
Also I think a flasher would be needed to implement such an idea anyways.
well theres goes another useless post by me!!! lol
If you are going to promote TB at least do it right!!!, or better yet DON'T!!!