Unexpected!Mark Gatiss! Awesome Mrs Hudson! Everyone assuming they're a couple! (yes it's an old joke but it makes me happy so shush). Also, I appear to fancy Inspector Lestrade, which is rather unprecedented.
I thought they made an excellent Holmes and Watson - in fact the only jarring thing I would complain about was that they called each other John and Sherlock - assuming them both to be ex-public school it wouldn't have been beyond the realms of plausibility to have them call each other by their surnames, surely?
Anyway. Loved it. Moar now plz.