Yeah, this is a novel that presents real-life authors as fictional characters. Nevertheless, no, this Dan Brown isn't that Dan Brown.
In The Hours, Dan Brown is the nice young man who "kissed, courted, and proposed to his best friend's older sister" after coming home from the Second World War, and, in time, turned Laura Zielski into Laura Brown (3.8).
Dan is sweet, simple, and utterly ordinary (just look at his normal, everyday name), but he had a touch of magic and mystery about him after the war. As the novel's narrator tells us: "Less than five years ago Dan himself was believed to have died, at Anzio, and when he was revealed two days later to be alive after all (he and some poor boy from Arcadia had had the same name), it seemed he had been resurrected. He seemed to have returned, still sweet-tempered, still smelling like himself, from the realm of the dead" (3.8).
As a husband, Dan is loving and kind to Laura. He brings her roses on the morning of his own birthday, telling her that "[i]t wouldn't mean much of anything" without her (11.25); he goes to work promptly every morning and comes home for supper every night; and, most endearingly, he genuinely appreciates the role that Laura plays in his life. Just take a look at what the narrator tells us after Dan has blown out the candles on his birthday cake:
Laura says to Richie, "Did you make a wish, too?"
He nods, though the possibility had not occurred to him. It seems he is always making a wish, and that his wishes, like his father's, have mainly to do with continuance. Like his father, what he wants most ardently is more of what he's already got […]. Like his father he senses that more of this is precisely what they may very well not get. (19.10)
In the film adaptation of The Hours, Dan is played by the wonderful John C. Reilly, who captures the character's earnest disposition perfectly. Dan is perfectly nice and perfectly ordinary—the kind of guy who seems as though he's just stepped out of an Archie comic book, and might just as easily step back in again.