I am by no means condoning trading for Hall, because I dont want the Leafs to.
However, I want to address one thing people have been mentioning, saying stuff like "how much would he help us in the playoffs anyways?"
What I would like to point out is that on every other playoff team Taylor Hall has been on, he was the main player expected to produce points. He was those teams #1 weapon. On the Leafs he would be the 4th, 5th, or 6th weapon. What he would bring to the Leafs is a match up nightmare for the opponent. If the Leafs wanted to load up a line the opponent would have to match up against Hall with either Matthews-Marner or Tavares-Nylander and use a weaker defense pair/forward group against the other line. If the Leafs wanted to exploit depth they could run Matthews-Marner then Tavares-Nylander then Hall-Kerfoot/Thornton/Spezza/Boyd/whoever. One of those 3 lines would feast on the opposing team's 3rd D pair and 3rd/4th forward line.
Like I said at the beginning, I do not want the Leafs to trade for Hall, the resources and cap space could be better utilized. However, that is what he would do for the team if he were to be acquired.