The only valid reason I've ever been able to come up with, aside from the eventual possibility of being able to clone specific organs through an as yet determined laboratory process, is the obvious: reproduction.
Perhaps cloning will go the way of IVF, and become the method of choice for couples (infertile, homosexual, etc.) who cannot have children. Perhaps, too, it will eventually become the reproductive method of choice if a pseudobody can be developed to clone a fetus in the laboratory, thereby eliminating the need for the woman to carry a child full term or at all.
I recently listned to a neo-feminist that was spouting just this kind of announcement: "only when cloning free's women from the burden of childbirth will they be equal to men....," etc.
While I think this seems unlikely at present, it is possible if the research is allowed to continue. In fact, I think that there are likely many applications that we have yet to discover that the research will discover in the future.