Hehehe, that sounds awesome.
The reason this is so awesome is basically because both Dracula and Conan Doyle's Sherlock Holmes stories were written (and take place) in the same historical time period, in England; as well as Dr. Jekyll and Mr. Hyde, btw.
I think that period was a golden time for British fiction / thriller writers, as so many great books were written practically at the same time.
What I don't like about the idea is that it's a criss-cross between a realistic thriller and a fantasy one. Fans of Sherlock Holmes can say that Conan Doyle's stories are all about Holmes finding logical, scientific explanations to every "supernatural" occurrence.
(Like in Guy Ritchie's Sherlock Holmes film, which was IMO fantastic as he brought in a lot of action into a story otherwise very loyal to Conan Doyle's style of writing).
So yeah, unless Sherlock Holmes eventually finds a scientific explanation to Dracula's vampirism, I'd say the two are not meant together.
