Randi's sexuality isn't interesting. However, the fact that he made a public statement about himself regarding a topic that many people are uncomfortable with is quite outstanding.
There are countries, in this world TODAY, where someone could get killed for coming out.
There are many, many people who are gay, but are hiding it for hear they will be ridiculed by the religious right. It's a real fear.
If we lived in an ideal society, the reponse to this would be "so what?". Unfortunately, we don't live in an ideal society.
When leaders like Randi and others make public statements about their sexuality, it helps the "everyday" people to hopefully feel better about their plight.
I do think that this is relevant to the skeptic community in the sense that most people hate homosexuality because of supersitions. I have yet to hear a non-religious argument against homosexuality.