It was an example to make ppl understood that if you start with a media and swap with another disc the console continue reading the disc like the starting media type, so with the laser wave length for that media type (swap magic worked in this way).
I merged the Fight Round 3 USA PS3-PARADOX thread here... it's the same issue/topic, just a different title. And no, unless you have PDX's special loader/mod you won't be able to run the PS3 back-ups yet. They told me directly it's not possible simply by swapping discs, etc. But feel free to post any experiments here... just to stir up some discussion.