@nasser: Yes, but the jailbreaks get more and more difficult, because Amazon obviously considers them a threat to their brave new world and "secures" their devices better, i.e., closes the jailbreak vectors.
This jailbreak here already was a PITA and took weeks to find, and in fact ATM, we don't have any more aces up our sleeves. As far as I'm aware, nobody has yet found a way to jailbreak 5.3.8 (yes, we more or less regularly do look into it). So the PW1 can only be reliably jailbroken because it can be downgraded.
Now, if the PW2 does not want to install the PW1 updates (and I assume that this will be the case) ->
