I love anime and manga, don’t get me wrong. A lot of the stuff Japan produces is awesome. Sherlock is just one of those shows that wouldn’t work as a shojo anime. It would end up really sparkly and weird and awful.
There IS detective Conan, but it's not really about Sherlock... It's more like, this REALLY REALLY smart Sherlock-esque teendoes something magic and he turns into a little boy and calls himself Conan after Doyle, and he deduces crimes... or something along those lines... I totally agree though. Sherlock would never properly work as an anime. It would be just too weird. XD
I would actually be very happy with the Sherlock show being an anime, no matter what style...I just hope it wont be shojo, cause that would be freakin weird as hell!!! I can defiantly see it as a shounen.
I'm fairly sure there is a Sherlock anime somewhere... it's called 'Sweet Milky Holmes' or something? Anyway, Sherlock's a young girl with ridiculously long pink pigtails in that, so I think your envisioning is actually rather normal by comparison.