As a Kings fan, I think the Leafs can be huge winners in this trade if: (1) Muzzin stays healthy and helps them in the playoffs; and (2) they trade Muzzin at next trade deadline for a 1st and any prospect. That would be the best move for the Leafs, especially if they feel one of their younger right handed defenseman is ready to step in.
From a Kings prospective, we had to cash in on Muzzin now. He was playing peak in his career, and the Kings have passed on opportunities to trade players when they are peaking (e.g., Carter). Muzzin is a solid number 2, but you never know if his game could drop off because of age or if he reverts back to his old habits of turning over the puck and losing confidence quickly. The most important return for the Kings was the 1st rounder, because we need to get as many 1st rounders as we can from this draft to cover the field. I hope we can get at least one more, and have 3 1st rounders.