I've been in college for a long time. This semester I have an instructor who wants me to call her by her first name, another wants me to address him as Professor [last name] and another prefers Mr. [last name].
For most of my college career, almost all the instructors I've had have preferred to be called by their first name. I liked that. It somehow made me feel like they were more approachable. I understand the social need for formality and can respect their wishes to be called whatever they want, but I do have a difficult time addressing people as "Professor" if they haven't earned the title. While I understand the term "professor" has been accepted for general use, there is a little academic snob in me.
Colleges and universities often have academic ranking and if an institution has them, I'd prefer if the people who instructed there respected those titles if they are, in turn, going to demand a degree of respect by requiring students to address them by those titles.
Anyhow, I'm not going to loose any sleep over this. I'll call them whatever they want as long as they can teach me something and so far, all look promising and I think I'm going to enjoy them very, very much.