I used to be the biggest Paul Martin basher around but the guy played stellar last year. Total 180 degree turn from the past couple years. I say let him play out his contract. That being said, I don't think Martin's trade value would be terribly high. He eats minutes and plays solid. He's still a bit overpaid, just playing much better than when he first arrived in Pittsburgh.
I agree that Malkin had turnovers in the playoffs, too, but he's not a defenseman. Forwards have a little more leeway with that stuff. Letang would turn the puck over when he was the last guy back and that's a problem. His decision making was awful. The worst part was that neither guy sat a single shift for turnovers, bad penalties, etc. That's a coaching problem but Bylsma got an extension so that's a moot point, too.
If Letang's salary ended up in the area of 6.5 per, I say bring him back. Mike Colligan wrote a very good column about Letang that is kind of the same place I was coming from:
http://thehockeywriters.com/kris-letang-contract-negotiations-part-one/
I think the Pens need to get younger next year because it's time to crap or get off the pot with some of these guys. I want to see Bortuzzo, Despres, and maybe even Dumoulin or Harrington playing minutes on D. Same with Bennett in the top six up front and try out some guys like Uher, Thompson, Sill, and Payerl in the bottom six. The Pens didn't trust any of their young guys last year. Look at both Boston and Chicago, guys like Shaw, Saad, Krug in the lineup as regulars.