Prior to transition, I was strictly a straight male, with no attraction to men. Today, after 2 years on hormones and a year living full time, I have had a couple of encounters with men, and have settled into a long-term relationship with another pre-op transsexual.
We both intend to have surgery, and frequently talk about what things will be like after. We thoroughly expect to be together for the rest of our lives (hey, we're old so it's not all that long!), and the only question about surgery is whether one or the other should go first, so we can be an "opposite sexes" couple long enough to get married, or whether we should go ahead and schedule our surgeries at the same time.
Attraction to us is entirely about the person, not the plumbing.