They have a bunch of prospects, not proven NHL talent. Don't confuse the two. If one of the guys in the top 4 gets injured then the Penguins have a big problem. With the Penguins being a win now team, they need to get one more top 4 d-man, even if that means giving up a prospect or two.
I agree with what mpp9 said about going through the growing pains with Despres now, and hopefully getting Bort some playing time, even if it means having to dress 7 Dmen some games. You're talking about making a trade so we're "covered" in the event of a hypothetical injury. We may not ever get that injury, and even if we did, the trade route could be a bridge we cross then. Crossing that bridge now makes zero sense.
Ill add that Murray is not an upgrade over what we have. I'd rather stick with what we have. And to be honest, I wouldn't give TK up with the way he's playing this year short of bringing back a legit top line guy.
I'll see your Murray comment, and add one about TK.
I like Murray, but (A) he probably wouldn't work well here in the Pens system with the way we like to play, because his skating is only mediocre, and (B) the Sharks are in win-now mode even more than the Penguins: their coaches & management staff's jobs are on a much shorter leash; and many of their core players are on the downsides of their careers. They are not going to trade Murray and he is not available. It was some HF-board guy's fantasy, and now people are talking about it like he's actually available. He's not.
Also, regarding TK: I've been sick of hearing how bad people think this guy is for the last 2-3 years, and the never-ending talk of how we should trade/buy-out/dump this player. Can people start finally realize how good of a player he is for us, on a winger-starved team, and how unlike other solid wingers like Cooke & Dupuis, he is about to enter into his prime years as opposed to his back-9? Start realizing instead: he's a good player, his coaches like him, his teammates like him, he enjoys playing here, and took a "hometown discount" to do so last time, and may do the same on his next deal. We need to keep players like this and add from there. So start showing TK some respect, because all the players & management within the organization seem to do so.