Is public speaking a talent or a skill?
Talent: a special natural ability or aptitude
Skill: the ability, coming from one's knowledge, practice, aptitude, etc., to do something well
If you think of public speaking as a talent, and it's one you don't have, you will fall into the trap of comparing yourself to others who have (what you perceive to be) "natural talent." You will see yourself as deficient in some way. You will convince yourself that you can never be as good as "so and so."
If you think of public speaking as a talent, and one you do have, you might think you don't need to work at it, because you're a "natural."
If you see it as a skill and recognize that everyone has to put in the time and effort to improve, you will get better.
Yes, there are people who have some natural talent. But every great speaker has had to work at it, and continues to work on those skills every day. Talent may give someone a foundation, but training is what makes a complete speaker.
Just look at the raw talent that passes through the audition rooms on American Idol every year.
There are some singers who have amazing voices, but no vocal control. Or they have great voices and control, but lack connection with the audience. Or they have great voices, but their movements are awkward (oh yeah, Taylor Hicks actually won). It takes more than just a great voice to be a great singer.
Whether or not you have "talent," develop your skill by practicing - and by taking every opportunity to speak.
Do you have talent or skill? Or both?