The opening-week hype is over, and beginning tonight, Fallon settles into week two. He should be very proud of himself, given what he’s accomplished already, and tonight’s installment sets out to please many audiences at once. The scheduled guests: actress Reese Witherspoon, who, like many guests who will be appearing on Fallon’s show, appeared on Saturday Night Live during his tenure there; Fallon’s fellow SNL veteran Fred Armisen, starting tonight as the bandleader on Late Night with Seth Meyers; and rapper Rick Ross, who ought to take full advantage of Fallon’s fabulous house band, The Roots.