There's another reason to expect an increasing rate-- it's harder to keep secrets these days.
Yes.
Also, I strongly suspect that changing attitudes towards homosexuality in the US plays a role, although I don't have a precise understanding of how I expect that to work.
Speaking roughly: my intuition is that when X is bad, a lot of people who have minor suspicions that someone they trust is doing X are motivated to pursue those suspicions, but when X is really really bad, those same people are instead motivated to not think about their suspicions. And I think the ratio of people who think homosexuality is really really bad to those who merely think ...
As we did last year, use this thread to make predictions for the next year and next decade, with probabilities attached when practical.
Happy New Year, Less Wrong!