I'm getting a good laugh at the people who have decided to write off Dahlen already becuse he's not ripping up the AHL in his first year.
Honestly, the worst case on this trade is that the Sharks are no worse off than they were before it. There's little to no way that Dahlen is a longer shot than Karlsson to make the NHL, and a very good chance that he's going to end up the better player.
Last year at 20 Dahlen was PPG in the Allsvenskan with Timra.
This year at 19 Karlsson has 17 points in 47 games also in the Allsvenskan (but with Karlskrona).
As a 21 year old AHL rookie, being basically 30 points in 50 games isn't that bad for a guy that was, even at his draft, never pegged to be a top 6 scorer. Dahlen's projections were, to the best of my memory, always to be a solid 3rd line grind and score type winger. I don't see anything so far that precludes that from happening.