If he's to be fired within the season, it certainly doesn't need to be done soon. I think this season is beyond salvageable. The only benefit of getting a new coach in right away is to get a few games with the Bruins under his belt this season before making a genuine try next season...and that only works if you've got a guy in ind that you're sticking with for more than year. I think Cassidy would be the most likely in-house Interim Coach candidate, but I'm not convinced he's the long term solution yet. Giving Cassidy a few extra games this year doesn't do much, so you may as well keep Claude.
Heck, keep him as long as possible to screw up other teams. Would the Isles jump at him? Maybe. Would the Habs? The fanbase loathes Therrien, and Claude's a Francophone, but not while they're on top of the standings. No reason to wrap Claude up with a bow and hand him to another team now.
I'm a little surprised there's been no announcement yet, but that makes me think he's going to hang around for a bit....but I've been wrong before...