My head is near exploding, as I'm sure yours is, from all the APT news. It's everywhere, I swear I saw it on the cover of the Weekly World News.
What annoys me is that the first several times I heard about an APT, "they" were basically describing any other virus or malware. The only difference was that the writers did a better job hiding their command and control, and they used more, and varying, ways to hide from AV and stay resident. This is a lame term as there is no line where quality achieves the level of Advanced!!
After hearing about the nature of the RSA breach, I have decided to only give credence to those who refer to an APT as an actor. APTs are not code. An APT is someone, some organization, or a nation state who is well funded, highly sophisticated, and persistent in their goal to compromise something.
I went to Wikipedia to see what the masses were saying, assuming the worst. Wikipedia agrees with me? I may have to turn in my security spurs. :-P
Proper use, "I am an advanced persistent threat".
Improper user, "I created an advanced persistent threat".
You can kill or jail an advanced persistent threat, but you can't delete it.