I noticed in the first ep of S2, there was a headline in the paper about the renovations at St Barts and I'm sure that must come into the solution. And he enlisted someone with access to bodies etc. I haven't read anyone's theories, but I'm sure there's some great ones out there.

Or there's this little piece of fantasy which I adore!
(http://s1106.photobucket.com/albums/h363/starrylizard1/?action=view&current=Sherlockintothetardis.gif)