Or....
Bethesda/Obsidian could make a computer program that can unencrypt A Fallout 3 or New Vegas save and have options for modification. That would fix a lot of problems with game-breaking glitches as well.
Sony's program encrypts the save files Bethesda/Obsidian can't do a thing about it.
Bethesda/Obsidian could release a program that acts like a game on PS3 that allows you to access console commands and install mods that are on a USB.
The one thing you said that is plausable is, they could allow access to console commands. There is nothing about the ps3 or 360 that somehow prevents the PC debug menu from actually functioning. It just require a little bit of extra work. They'd need to add button combination command to bring up the console menu, and have trophies/achivements set to be disabled if the console is used. And some console commands simply couldn't function but most would work just fine. I point to the game Two Worlds II a sandbox RPG game where the console menu works on all platforms.