BTW I'm glad we got so much of Mycroft. I love him to bits. Of course he was "in the know" and probably behind the death staging. If anyone had the means to pull it off, it's Mycroft!
Of course Moffat and Gatiss like to play so they left it ambiguous: did Sherlock tell Anderson the truth or did he not? I tend to believe he actually did -- probably because it goes with my theory about Mycroft feeding Moriarty infos on purpose instead of having been fooled (in my book Mycroft is indeed smarter than anyone) --, but I don't mind not knowing for sure. I like the idea of the writers making a pied de nez to the audience and embracing the role of the magician. Show the turn, makes a big show of the prestige, but never reveal your trick because the trick will be disappointing and deep down the audience doesn't want to know.
The episode made me smile and laugh quite a bit, especially the "fu...cough" moment! I know sometimes I'm twelve.
I loved the jokes and puns, and how The Adventure of the Empty House became Anderson's fan group, called "The Empty Hearse". I must say that Anderson's theory was fun and he is obviously a Sherlock/Molly shipper. Also Pierced Girl and her Sherlock/Moriarty theory must represent fangirls who are into slash, right?
I'm sure the "gay" thing running through the episode will annoy some people, and they might blame Mark Gatiss. Yet it has never been more obvious that although Sherlock and Watson are a true couple, there's nothing homoerotic about it.
But the episode wasn't only pure meta. The Sherlock/Watson reunion was the core of it, and it was handled quite well. The moustache thing called Battlestar Galactica to my mind. Bill Adama let it grow during the year that was squeezed in at the end of season 2 too, and shaved it only after the reunion of his people! Very soldier-y.
Behind the fans' "how?" (how did Sherlock do it?) there was another "how?", the John's "how" (How could you do that to me?) --which echoed the "underground network" word play-- and that was what the episode was all about. Freeman and Cumberbatch played the emotional moments quite well. Mary fitted in perfectly (although in The Adventure of The Empty House she's already dead...but I think that in the books Watson was married to her before the Final Problem so our boys have already changed Mary's storyline) and apparently she's played by Freeman's real wife, while Sherlock's parents were played by Cumberbatch's ones!
I am not sure the skeleton's stuff (an Anderson's fake) was necessary but maybe I missed something there. As for the terrotist stuff, it really looked like an excuse to have Sherlock and John work together again. But I guess the switch-off button was meant to be an echo the "anti-climatic" version of "how he did it", hence the inserted scene between Sherlock and Anderson.
So in terms of plot the episode (the Moran's plot) wasn't brillant, but this was obviously not a plot-oriented oriented hour. It was an episode to reunite viewers and characters, and I really liked all the characters moments...especially everything Mycroft of course!
Now I expect the second episode to be plot heavy and focus on that mysterious blue-eyed villain who abducted Watson and who was watching the video in the end.