In Italy for the original Ithaka we reserved (and didn't even prepay) and then, when the product became available, the shop website suddendly had an ego case available, which was actually Ithaka. One ordered this ego case (an expensive one - 135 €

), along with a password we received via PM in a forum and indicating the nickname, and we got our Ithakas.
Of course the ego case was visible to everyone visiting the website, but without pass and nickname it was impossible to order.
Maybe something like this could be done for Proteus, of course hoping that no idiot gives the password away to people not in list.