Summary: Sherlock Holmes faces his deadliest ennemy, Pr Moriarty, while his companion Dr Watson faces a greater challenge even: getting maried to Mary while Holmes gets in the way. For those who've read the Canon, you know what Reichenbach means - and they will make a stop by it.
Personnal Opinion:
I hadn't been a fan of the first movie, even though I think J. Downey Junior and Jude Law made a cool impersonation of Sherlock Holmes and Dr Watson. I thought the story lacked in cleverness and that Delowney was a bit too unshaved for my taste.
However, I enjoyed this movie. I'm still not quite at ease with action taking over most of it and with submachine gun fights in an steam punk atmosphere, but if I just see this film as a huge fanfiction rather than as an interpretation of the Canon, then hell does it kick ass. The slow motion scenes are gorgeous, and their use in showing how Holmes analyses fights did not get superfluous.
Pr. Moriarty (Jared Harris) was amazing, quite classic but really cool -his eyes, they're always as cold as a murdering knife... I'm not happy with the depiction of him being a villain being explicitely linked with him being pro world wars - I think that too classic a "he likes world wars so he's nazi-to-be bad" trope. Why does the greatest villain of them all always have to be a pro war opportunist?
The character of Mary, which I didn't like at all in the first movie, was well handled in this one, and it's not easy to make the wife of one of the sexiest characters on screen lovable to a crazed fan - but this movie was up to the challenge. The other main female character -Simza, played by Noomi Rapace (from Millenium) was cool too, and I have to say that I was really happy another one (no spoiler) got to disappear quickly from the movie - I don't like Sherlock Holmes flirting with people, that is just too unprofessional of him. Ah, yes, did I mention that we get to see Stephen Fry as Mycroft -naked?
I'm still not convinced by the story, its outcome is too improbable for my taste, but I've enjoyed the characters's relashionship (sorry Watson - partnership) and would re-watch the film just for that. The Reichenbach fall was a really good moment, and the exact last second of the movie was such a HUGE satisfaction that I'm now going to run naked in the snow.