from everything I've been reading lately, it really depends on the particular TSA agent. There are policies in place for transgendered people to not be "outed" in regards to the gender marker. If you have a current picture and your name change, I wouldn't expect any problem.
I am going to be flying internationally for my FFS in august, and by that time, I will have had the legal name change AND the marker on my passport and license (As florida has changed their laws....)... Interestingly enough, there was a lot of information about the body scanners on international flights causing some TG people problems... But whatever. I believe in when you smile, are confident, and have a good attitude, a lot more can get done with less problems anywhere. One thing missing from these stories, is how the person themselves carried themselves, and also what the other circumstances were. I mean, random searches really CAN be random.. lol!