Reilly for #5 is a must if it's on the table. We have four first pairing guys, all young. Reilly is the least known and most expendable, and likely has the most inflated trade value out of anyone because it's 100% based on hype and potential. If it lands us our top line center for the next decade plus, do it.
As for Phaneuf, said it before and saying it again, he had a bad playoffs and really isn't true captain material. And he's moving into the final year of his deal. Could totally see them wanting to trade him. Doing it leaves us weak back there unless Reilly is ready to step right in. If he is and we can get our center for Dion, that's maybe a franchise making deal. Trading one of our older core players, replacing him with an equal newbie, getting an elite newbie at center, and shedding lots of space off the cap. High risk, but I think I'd do it before trading Reilly and roll the dice on two elite prospects stepping up.