Indeed! I do think the writers missed the boat on the amulet. Jensen actually touched on that at JIBCon, saying that he had spoken to Kripke who said he wanted to get rid of the amulet and all of the other stuff Dean wears. I honestly don't think Kripke thought it all the way through -the amulet became the "thing with which we find God" in Season 5, but he may well have forgotten (which is weird, but whatever) that it was, primarily, Sam's first real gift to Dean, and a really strong symbol of their bond. So having that left literally in the trash and never picked up again is a hell of a wound for much of fandom (myself included).

The voicemail bothered me less, inasmuch as I know Dean has no way of knowing about it, and Sam is too filled with doubt and self-loathing to ever bring it up, since he's convinced that A) it was Dean and B) Dean was absolutely right. So while I *want* it to get brought up and resolved, I'm less unhappy than I am about the amulet, which they BOTH know about.