Lara Pulver, who has signed up to play Irene Adler in the 2nd Series of Sherlock for A Scandal In Belgravia, has been interviewed by Digital Spy:
On the episode:
"Steven Moffat's written an episode about Sherlock dealing with what love is, rather than Sherlock really knowing what being in love is. We're both very much playing a mind game with each other. We've met our matches with each other."
And on if love is blossoming between Sherlock and Irene:
"It's kind of deeper than romance. It's kind of infatuation."