He's capable of a 50 goal season easy.
Put him on a line with a pure passer/assist-machine/gamemaker like Thornton, Lecavalier, Spezza, Toews, Backstrom, Stastny, or Getzlaf, to name but a few in the NHL right now.
Thornton - Though I like him, he is too old. I would rather have a player closer in age to grow with Kessel.
Lecavalier - Too expensive, both in what it would cost to get him out of Tampa(unless they got desperate) and the cap hit.
Spezza - NO ! Too expensive cap hit, and for the return ... please, it is an easy call. He is far too soft in my opinion.
Backstrom - Is Ovechkin making him look better then he is ?
Stastny - Cost too much in trade to get.
Toews - I would love to get him out of Chicago and the Hawks are going to have cap issues. Both Toews and Kane are RFAs at the end of the season.
Getzlaf - My first choice and I do not think it would be as difficult to get him from the Ducks as one may think. I am not suggesting anything or dreaming, just financial reality with US based teams.
It will probably never happen.