Expect this domain adoption to lead to an extended excercise in frustration, polictics, censorship and name-calling. ICANN is making the TLD available (for $75 per domain) so that porn sites can move in. What's not being said is that most porn sites probably won't move there because it makes censorship of their site(s) extremely simple.
An good example of this is "www.whitehouse.com". The site uses that domain for two reasons: notariety and to attract fat-fingered surfers.
What happens when ICANN figures out that very few web sites are buying their $75 .xxx domains and are sticking with their $5 .com/.net domains? It's likely to involve parental controls, loud proclamations of "we're doing it to protect the children", and attempts to force migration to the .xxx realm.
It'll only get nastier after that. Because I periodically write about things that are unpleasant to some (and sometimes include the word "fuck"), does this site deserve an adult rating? Who gets to categorize the site? How long before people realize that the Internet is an adult tool, not a child's playground?
Hopefully, the .xxx domain will exist to hold only those sites that want to be there but (feel free to call me a pessimist) I don't believe it'll exist more than 6 months before either the legislative branch or the media calls out the lynch mob.