Actually, it didn't for me. I click on "log in", then click the Clickpass drop-down, type in my own OpenID, it goes through to MyOpenID and verified that.
Then it takes me to the "merge with your existing Hacker News account", and I type my correct username/password, but then I get redirected back to News.YC and a blank page at something like http://news.ycombinator.com/x?fnid=j3tO1pS8ox