This How Do You Know trailer looks promising. Closely observed relationship comedy is what writer-director James L. Brooks does best. He sweats years over these originals to make them come out looking effortless and funny, and only rarely does he miss (Spanglish). And each of the stars–Reese Witherspoon and her two swains, Owen Wilson and Paul Rudd, and Jack Nicholson as his father– look sweetly comfortable inside their wheelhouse. I’m there. Sony opens the movie December 17–an award-season friendly position.