"Sources tell TSN the Toronto Maple Leafs have received what the team considers to be a significant offer for defenceman Tomas Kaberle."
http://www.tsn.ca/nhl/story/?id=282846
Kaberle has been rumoured to a few teams in the past.
The Kaberle to San Jose rumours have been active for few years now.
This morning TSN reported that Toronto was interested in Ryane Clowe but Doug Wilson's asking price of the 7th overall pick was too steep.
Perhaps when Burke told Wilson that Kaberle was available that changed things.
Kaberle for Clowe straight up makes a lot of sense to me for both teams.