I think it's funny you blame PD for the fact they had to block trading to take care of people exploiting the game.
Let's look at facts:
1) PD orignially blocked game-save back-up's (obviously to prevent this whole duping issue)
2) People whined and complained (much like here)
3) PD saw a legitament problem with the fact that people couldnt backup a gamesave. So they allowed it (hoping people woundn't exploit the game too badly)
4) 1,000,000,000 X1 hit the market thanks to duping
5) Idiots start selling cars on E-bay
6) PD must stop illegal trade - must take steps against duping (Ebay's the problem here))
IMO - PD has bent over backward to quiet all the complainers, now they've changed rules so many times they've pissed off two groups (dupers/non-dupers legitament traders). You can't please everything and the system is broken, I agree with the limit given the situation.
Would you all prefer gamesaves being blocked again? But then what do you do when you upgrade your HD? Or get a new PS3?
There isn't an answer to this and someone is going to be mad - personally, I say stick it to the dupers..... and it that hits legitament traders, well, sorry - blame dupers not PD.