My feelings on the topic are similar to iceman's, though possibly for slightly different reasons.

What bothers me is not the fact that Eliezer's sex life is "unusual", or that he talks about it, but that he talks about it in his capacity as the chief figurehead and PR representative for his organization. This signals a certain lack of focus due to an inability to distinguish one's personal and professional life.

Unless the precise number and configuration of Eliezer's significant others is directly applicable to AI risk reduction, there's simply no need to discuss it in his official capacity. It's unprofessional and distracting.

(in the interests of full disclosure, I should mention that I am not planning on donating to SIAI any time soon, so my points above are more or less academic).