I watch more NBA than most people on this board i assume. Stevens has the Celtics in the right path, they have a decent young core. However, they have no big guys worth a damn. Ask any Celtic fan, they hate all their big guys and would be more than glad to trade them away.
The celtics have the potential to land the #1 overall pick this summer along with a couple other first round draft picks. If they get a top 3 pick, a couple quality bigs, along with a bench, they could be right back at the top of the east.
The only way i see Stevens wanting to LEAVE the NBA is for his family. If he wants to spend more time with his family with more time off in the summer, then he will come back to the college game. At this point. Brad is working from October -May, not to mention half the games are spent on the road traveling to other major cities around the world.