Stop with the "much younger" crap. Yes, he's younger than Tallinder (who turned 34 less than 2 weeks ago), Salvador (turning 37 next month), and Zidlicky (turning 36 next month). Volchenkov himself is turning 31 next month, so trying to paint a 4 year difference between him and Tallinder is disingenuous when its the difference of 37 months. And Volchenkov is still 30. He's not 25. He has mileage on him because of his style and has been an occasional injury concern. I'm not saying this is the equivalent of him being 35+, but lets not act like he's beginning to enter his prime here. On top of that, Zidlicky is on an expiring contract and provides an offensive dynamic the others on this list do not. Salvador was just named the team's captain and they do not desire to move him.
And don't overestimate the no trade clause. It LIMITS where you can trade him. It doesn't mean you can't. If his role is going to be limited here, he won't be happy here and will be willing enough to accept a trade. You're just limited in your potential trade partners. Likely will limit it to contenders, which is where he would likely want to be anyway. Not saying his role WILL be limited, but if they decide he's the odd-man out, his minutes would be scaled back, and they call tell him that. He would be far more open to moving in that case.
End of the day, Lou is going to trade whichever one can get the best return without compromising the overall talent and effectiveness of the defensive unit. With the depth they have, that could be just about anyone in all honesty. There's no clear cut choice in the bunch.