Since I actually know the presenter of the asexuality workshop and spent some time with her this weekend, I can add a bit of insight to your question, RP.
She dates quite a lot, and she is very upfront about her asexual orientation. Apparently there are quite a few men and women out there who don't regard sex as *the* priority in dating, and many of these people are, in fact, poly (she is poly as well as asexual, and she is also bi-romantic).
I spoke to a few men in the group here about her, and all of them thought her presentation was awesome. I didn't get any regretful comments about the fact that she was "unavailable" for sex. But then, we *do* have a pretty exceptional group of poly men in our community.
One of the reasons I wanted her to come speak to the group was because poly discussions often centre on sexuality within relationships, and the different levels of need and priority that are placed on sex. I really liked how she stressed that sexual orientation and desire are a spectrum rather than concrete labels, and a fluid identification that can and probably will change over a person's lifetime. I especially liked how comfortable she was with herself. The presentation really brought home, for me, how important respect
is in relationships.