Slash possibilities completely aside, they just look so dapper! And a little Victorian-seedy, which is kind of hot too.
Having been listening to another Holmes story on The Classic Tales podcast, I've been thinking the casting of Robert Downey Jr. is not as weird as it seems on the surface. Holmes has a quick, rational mind, yes, but he's also got a lazy way of tossing himself into armchairs and leaning back with his eyes closed to listen to people, plus that whole wild cocaine-taking side. The role fits pretty well, I'd say. (Plus, he's a good actor, so I think he can tackle it.)