"Moffat mentioned at the DW panel at comic that season four of Sherlock has already been commissioned. So I highly would give them the money if there wasn't going to be another season.
And yes, Moffat is the King of Trolling. "
"Benedict Cumberbatch and Martin Freeman are both signed up for series four, so we are safe, for now. I reckon the wedding is John's, the rat refers to The Boscombe Valley Mystery of the cannon, and bow... I don't know. I really don't…"
"I'm assuming they're having a season for each of the compilation books, which would mean Series 3 being based on Return of Sherlock Holmes and then there being a Season 4 for His Last Bow and Casebook."
"Well, the "wedding" is presumably John's marriage (either to Mary Morstan or the mysterious second wife of his), "Rat" could be the Giant Rat of Sumatra, the case mentioned but not expanded on in canon, and Bow is probably…"