you can back up it ofc but i don't sure if all of it
i just done it cause i going to make the new PS3 to my main one so i can play with you and others in the net and etc
and i hate the fact that it only have 160 gb compared to my moded one who have 320 gb... with all the stuff i may buy i will eat it in a week :0 (when i will have money ofc lol xD)
So i thought it will be the best to do it before i will actually play dozen of games on it
my trophies got "deleted" anyway though since i opened new account not long ago
lucky i never really care about achievements and trophies, not the for trophies that not give you anything anyway and not even part of the game but part of the PS3/xbox network xD
Neh i don't think i need to go that far as for youtube it xD
i already use PS3 with HDD daily(the moded one can read games from HDDs and have far more complex options in it since it use 2 OSs, same to moded xbox or even for PC xD)
beside there is not much to back up from the new PS3 to begin with :3