I personally don't think there's a chance in hell he's still alive, and here's why: from what I could tell, Tupac was not the type to go and hide in shame after being threatened. Remember seeing all those interviews? He was in the camera's face, almost laughing at death. Biggie, on the other hand, started to get paranoid that his own death was in the future. Tupac stared death straight in the face, so him faking his own death just doesn't seem to be within the relm of something he would do.