I don't think Janssen is a replacement for Clarkson, but I also don't think Clarkson is deserving of "slag-free" treatment. Since we've been removed from Devils hockey for a while now, it took me some time to remember just how bad of a season he had. 18 points in 82 games. He did manage to have 170 hits, for whatever that's worth, but averaging about a point every 5 games for $2.67 million is just eating away cap space for underachieving production.
I understand Clarkson gets paid 5+ times what Janssen does (well, assuming Cam makes $550K, but stranger things have happened). But in all honesty, he gives you 5+ times what Cam does. Even last year. So let's lay off the Clarkson slagging. Cam doesn't replace him because he's a spot starter who might play 5 minutes if a game is out of hand.
If you bring in Cam under the pretense of playing him 82 times and remove Clarkson from the roster... your team just got significantly worse.
Everyone knocks Rolston (myself included) because he's likely for a 40-point season over 82 full games. That's almost double Clarkson's cap hit for double the production.
Janssen won't play 82 games; I don't think anyone is suggesting this is a one-for-one move. But if Janssen becomes the 4th liner to replace Adam Mair's spot duty (or what he should have been receiving, anyway), and Clarkson gets moved, that opens up roster spots for guys like Zharkov, Tedenby, and Josefson to play more games...and it clears cap space, which would help in re-signing Parise or potentially fitting Larsson onto the team.
Biggest downside: Devils would lose another physical winger capable of playing top-six minutes if needed. With Clarkson moved, the Devils' most physical forwards are Pelley and Janssen, with Palmieri and Zubrus distantly trailing.