It's rather yet to be decided if that scene reveals anything about character isn't it? It's difficult for it to 'reveal' anything when nothing has happened subsequently yet - unless someone has a crystal ball (or pirated copy of the next episode) to hand.
Also, yes we know he's a sadistic ruthless bastard - so it would be rather out of character for him not to continue displaying it. It would have been more ridiculous for him to marry her and then suddenly turn into a charming prince lovely would it not?
Who knows, maybe Sansa will now be a ruthless scheming bitch now bent on revenge and will outmanoeuvre RB through all that Littlefinger has taught her...
Nice to be able to speculate seeing as this is utterly different to him.. (don't read if you don't know the books and want to read)
married to a fake Arya in the books and Sansa doing something else completely different elsewhere