Phaneuf's value to the Leafs right now is as a minutes eater, nothing more. He doesn't play into the long-term plans of the team. Someone will give up a mid round pick+decent prospect+salary dump for him. Kessel is more contentious, could play into the long term future as he'll be only 33 when we're really hitting our stride. If we can get serious value for him (such as NJ or WAS first round pick, I've heard Kessel for WAS pick+prospect+Semin salary dump) he'll move, otherwise they'll likely try and integrate him into Babcock's system.
Interesting take on the situation. My first reaction when I saw the hiring was the exact opposite in regards to the future of Kessel and Dion. Granted the Red Wings needs are obviously different then Toronto's, but my first thought was "Since Babs apparently wanted Dion in Detroit, I'd think he's very likely to stay and if anyone's getting moved, it'll be Kessel."
It'll be interesting to see what they get moved for, assuming one or both of them to get shipped out for future assets. The closest thing to a Kessel-type of player/deal that's been made recently was the Nash trade IMO, so I'm using that as my benchmark. Granted they're different types of players, Kessel's more of a pure goal scorer while Nash is a better all-around player, both are 27 year olds at the time of a possible deal, and they're both locked in long term at similar cap hit and AAV. Problem is not many teams have the cap space AND the bounty of expendable assets that would probably be needed to land him, unless they want to blow holes in the core of their current roster, also similar to the Nash deal and how the Rangers had no depth until we traded away Gabby. Buffalo, Florida, and the Isles are 3 teams that jump out to me, but Kessel has that partial NTC to block a possible move, and Buffalo already made a similar deal when they brought in Kane.