The ellipsis, like the apostrophe, is used to indicate an omission. Increasingly, it seems to be used as a way to indicate the end of a humorous statement. People used to use exclamation marks for this purpose, until F Scott Fitzgerald made them too self-conscious about it.
I admit that I have to fight the urge to use ellipses myself but they are becoming a plague on our nation's prose. We must fight this pernicious threat.
Continue to use ellipses by all means, but use them wisely and sparingly.
d.