What makes Sherlock Holmes iconic? Oh, I dunno, could it be his powers of observation and his clever deductions? Reboot, don't reinvent. At least not if you want your central character to be Holmes and not some original character who happens to share the same name. Want a Conan Doyle character who might credibly swashbuckle? Try Professor Challenger instead. Or move further afield to Allan Quatermain. All of those characters have baggage, but I'm sure Guy Ritchie can blithely ignore it.
(Discovered via agilesreader.)
PS to all concerned: Hugh Laurie is already playing Holmes weekly, on American television. If he's smart, he'll find new territory.