I think to be "dating" someone implies that you are serious about that person enough to forego other dates.
I don't think dating equals commitment--I think if you are committed to someone, then you usually say that you are "in a relationship."
Well, Music, what do you think if there are several people in whom one is particularly interested; they are suggesting dates only erratically - like, once every few weeks; and you are not intimate with any of them.
No I personally think that dating more than one person at the same time is fine if you're not telling any one of them that they are exclusive.
I think dating means you like them and want to spend time with them, however not necessarily exclusively. I can see "dating" several people, but I agree, the terminoly would change with an exclusive relationship.