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.
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.
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.
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."
I think to be "dating" someone implies that you are serious about that person enough to forego other dates.