That was the point of the movie ending, wasn't it? Daniel was to start a new while Jack would be returning to mend the old.

I think it's a TV faux pas to think that stable (not the best tern here but go with me) relationships would bore the viewer. The lead guy always has to be single, either through divorce, separation, or death. This leads him open to various sexual and romantic escapades so that by the end, he can finally realize that love has always been there in the form of his female lead counterpart.