Well, Hall would have had 50 rather easily this year IMO if he didn't get hurt. He was starting to dominate games and probably finishes with 25+ and 50+, so I expect 60+ points from him next year, similar to the years of JT and Duchene.
The problem is he plays a rather kamikaze style and still needs to fill out. Teams tend to adjust how they play against you after your rookie year, so the faster he fills out that big frame the better so he won't get pushed around as much.
Furthermore, the Oilers PP was probably one of the worst ever in the modern era, so it's tough to pad his stats with some PP production.
If a kid like RNH is centering him, Gagner finally breaks out with him, or Horcoff starts to gel with Hall again, AND they can at least have a mildly respectable PP (15-20th in the league), then I think the sky is the limit over the next couple years.