I've been waiting for quite some time for this, but as Plexihost said, if it's not enforced, it's wasted. There's so many TLDs these days that it's become a management nightmare. If anything it's now forced many companies to not only register their .com name, but also .net, .org, .biz, .us, .ca, .co.uk, .mobi and a slew of other names just so that their brand doesn't get tainted by some other person.
Enforcement will be key, but forcing users to use "xxx" as an extension will never work as the .com's will still be around (or will be snagged up by MLM's wanting some instant pagerank boosts.
Also, what Steve said is valid too. I personally don't constitute adult novelties as "pornographic" although others do. There's many a swimsuit picture that can be put into either category, but again, it all depends on who is making that call. Is seductive pornographic, or is it art? The line will become very blurred.