127 domains that I used in the past point to xenfans, they got a lot of spam on vBulletin in the past.
Yes, it's a new site, and surely over time spam becomes more annoying, we will consider turning mail verification on by then.
Every spam we do get, we review. We take the time to go through the account, the access_log and error_log for the ips used, the referrer data, and go through the blacklist report sites, etc.
Having good contacts with data centers helps too. They get a bi-monthly report with a log file they can process. Which helps prevent repeat offenders on the site to crawl to almost 0.
As time passes, we will turn on email verification, add additional q/a questions, and perhaps moderate 0 posters. Install stopforumspam plugins, etc. We've been running the site since July 2010 and spam is minimum, so can't justify compromising the user experience vs 10 bots a year.