There was a nice article about Sherlock in Digital Video magazine maybe a year or so ago.
It mentioned it was shot with two Arri Alexas most of the time, but they also used DSLRS for certain shots.Most interestingly, they would take a series of still pics at different focal lengths, then stitch them together for a staccato kind of zoom that was very effective dramatically.
They also talked about how they created the text/numeric images when Sherlock is thinking.