Before Orochimaru dies, Kabuto transfers his DNA to himself. So over time, Kabuto is becoming more and more like his master. His techniques are the same and his power is TREMENDOUS!
Kabuto has not died yet; however, i sense a change in his loyalties to be approaching soon.
No...
Kabuto try to kill sasuke in "Naruto episode 51."
Actually.. Yes he does!! Sasori and many others are brought back to life( in the manga ch.518) for the Ninja war, thanks to Kabuto :) (note: he does die after Kankuro brings him to peace about his puppets)
Yes kabuto found orochimaru's body when he was died and sewed it on so now orochimaru is taking over kabuto's body slowly