Well when I was drinking I would be interested in sex whether or not the chemistry and feelings were there or not. It was more about whether I needed sex or not. It was very selfish. Once I got sober, physical attraction and good communication became a lot more important to my level of interest, but if it was there it was wonderful.
The chemistry between me and my current partner is very strong, even after 3 years, and we have a very active and fulfilling sex life. So yes, the libido definitely returns, assuming the other factors are in place.