What is the percentage chance of these trades happening?

I'd say none. The Sharks aren't really in the market for a guy like Kovalchuk since they just picked up Heatley this year and I could be wrong but I don't think they can afford to sign Kovalchuk to the type of contract he will likely be looking for this summer. So trading a solid player entering the first year in a four year contract along with draft picks for someone who likely wouldn't be with the team past the end of the season would be kind of dumb. As for the other deal, Kaberle has a no-trade clause and Brian Burke has said many times that he will not ask any player to waive their no-trade clause. Even if he didn't have a no-trade clause Kaberle without the draft picks could bring in a better deal the Ryan Clowe and Kent Huskins.

I think Kaberle is an important defenseman to the leafs so I don't think they're trading him for Ryan Clowe etc. But Kovy won't fit in with the sharks salary cap.

I'd say zero, Clowe is a great player that they may keep. Sharks don't need Kovy, but then again, could use another D like Kaberle since Blake is on his way out.

Zero, Kaberle currently commands a front line player and draft picks. Pittsburgh recently offered the Leafs Talbot and a 1st rounder for Kaberle, which Toronto declined, and two other teams have offered Toronto front line players and a first rounder for Kaberle. Tomas Kaberle is amopng the NHL's top 10 defensemen in Central Scouting and is the 2nd highest scoring defenceman since the lockout......he commands a high price. Boston offered Kessel and 2 draft picks for Kaberle and a draft pick. Toronto will get a lot for Kaberle, or he's not going anywhere.