I say he wins 4 or 5 slams, maybe even 6 if he is lucky. murray is as talented, maybe even more talented than djokovic and they are basically equals. murray is forever improving and djokovic has already hit his peak and will surely see decline within the next 2 to 3 years. murray i don't see declining for a while and could still be a force (and top 4) when he is 30 years old, that means many more chances at slams and i am sure he will win a few in time to come.
"I rest my case. Federer needs to win 28 slams, twice more than Nadal to be in the same conversation with Sampras." A famous quote from helloworld.