From a study presented last year at the International Conference on Human-Robot Interaction, in New Zealand. Participants were asked their opinion of various capabilities a sex robot might have. They are listed in order of most to least desirable.

Moves by itself

Obeys orders

Responds to touch

Can talk

Can learn new behaviors

Can understand language

Can recognize objects

Can hear

Can remember past interactions

Can see

Can take initiative

Recognizes human emotions

Has feelings