Tupac is dead. Like and unlike most artists, Tupac created a vast collection of acapella tapes, or verbal tapes, with only the lyrics for future recordings, or just as garbage recordings that were to be used. Although I despise Tupac and everything he did, I believe he was a very smart man. He knew he was going to die eventually, so he made many more of these tapes than most artists, so they could be used post-humously (sp?).
Tupac and Notorious were both "taken care of" by Marion "Suge" Knight. Tupac was planning on leaving Death Row because of the violence affiliated with it (watch Ressurection, he appologizes for all the shit talking he did, and the East-West shit, Suge revved him up and supported this anger, and Tupac was blinded by it), and he was going to take all of the recordings and everything. He made this clear 4 days before the Mike Tyson fight, which was the night of his demise.
Strangely (permit me to rant my conspiracy theories here), I believe the United States government was somewhat responsible as well for the deaths of the artists. Why? Because both of them sturred up violence all across America, and both were affiliated with Bloods and Crips. If you ever watch Biggie vs. Tupac or Ressurection (I think), they explain that Biggie and Pac were under heavy surveilence of the FBI.....odd. It also peaks my curiosity that the government or police forces or any law affiliated firm in general has never put even a smidge of effort into solving their cases. Quite pathetic in my opinion.