The problem is that it will never work. ICANN holds no jurisdiction over anything, they are strictly a set of rules and not laws. They cannot punish those who deviate, nor can they force the governments of those who deviate to punish. ICANN cannot even revoke an address or even mandate that a certain entity can no longer buy addresses.
I've wanted a .XXX or some other higher level domain for quite some time for ease of administration, but even the best admistrator knows that even if the whole world followed the rules and kept all the ill-sites in this range, there is no block on this planet that will work unless you literally pull the plug (and now with WiFi USB keyfobs, this don't even work). However, I have never wanted this for the aide of parents. If your kid is surfing porn, then it's your own fucking fault you weren't there with them to help guide them in this thing called life (I don't care if you choose to restrict or to educate, as long as you do something to protect them)... or did you forget that was your job in the first place?