I don't like Mary because I don't like Mary. She was more than willing to kill Sherlock to stop John from knowing who she really is. The baby name thing. All of it. I've tried writing a couple of times and I see her as a plot problem. SusiGo said she didn't believe the "surgery" bit. Maybe what she meant was she's not "buying it" and neither am I. In fact, I'm not buying very much of her and John's relationship at all. This will be solved by Mary's death.

It's probably nothing, but we don't see a live action Moriarty until after the show is over. 

I think Brettholmes may be on to something here. These are, after all, stories and in every episode you have to overlook logical flaws in order to enjoy the story. 
Having said that, some folks think that Moriarty is going to stay dead and that it is through Jenean or possibly Mary that he will continue to be prominent in the new season.
Add st to the middle of Sebastian Moran's last name and you get Marys fake last name. 

I'm wondering if there isn't another reason for the Janine character. A Moriarty family connection? How might she and Mary have come to know each other? Why are we informed about the cottage and the bees? Why are we informed that CAM flicked her eye? What did he have on her? And, by the way, how did Mary get into CAM's office? Sherlock says she left the way she came but that isn't explained? Wouldn't Janine have seen the person who bashed her in the head? Any thoughts?

Assuming the writers keep to Conan-Doyle's story, Mary will die and John will move back into 221B. In the books it is never revealed how she died so the writers of "Sherlock" have a wide open field in which to spin their tale.
Information such as the elder Holmes's time in america and Mary's american connections are not added  just to fill out a script with words. They are calculated and discussed exhaustively.
I'll be very dissapointed if there are any anagrams involved

Sir Arthur decided Mary's fate long ago. It is my understanding that nothing in any of his writings excludes the possibilities of further siblings, either male or female. I very much liked the suggestion, made elsewhere, that Janine is a Moriarity sister. Of course, there could have been more than one of those as well.

Mycroft clearly identifies their parents as residing in Oklahoma. This happens around the 16 minute mark of the most recent episode. Mary is identified as having done work for the C.I.A. at around the 77 minute mark. The home where Christmas is spent may or may not be a Holmes family property but this is irrelevant. 

The various clues could all be "red herrings" but I'll point out a few all the same.

1.The Holmes parents show up simultaneously with Mary. They apparently live in America while Mary seems to have American connections.
2.It is made abundantly clear that she's bright enough in that "Holmseian" way.
3.Mention is made of "...what happened to the other one." without specifying gender.
4.In The Adventure of the Copper Beeches Holmes, at least twice, makes reference to a possible sister.
5.I believe Mary and Mrs. Holmes both refer to Mycroft as "Mike". Janine certainly does and she's Mary's friend.
6.Mary says that the elder Mr. Holmes is the sane Holmes but he suggests it's her.
7.If you listen carefully, Mrs. Holmes refers to her husband as "...your father." when speaking to Mary
Any takers?