You know, SPN just oozes irony. Do the brothers realize it when it applies to them?
At the end of this ep, when Sam and Dean are talking Molly into letting go, Sam tells her, "You don't belong here. Haven't you suffered enough already?" And that so gets a reaction out of Dean, who has been told more than once--and who feels in his heart--that things aren't right that he's alive, and who has suffered a great deal over the course of his years. Particularly in light of where it's going (what with coming from IMToD and CSPWDT and going toward WIaWSNB), I just want to ask Sam . . . "Soooo . . . You talk Molly into letting go, but what if Dean told you he was ready to let go? You know, during one of his many coronary incidences? Or mid-3rd season when y'all watch a father let his daughter go? Or when Dean's talking to Tess the Reaper later on? You're willing to talk Molly into letting go, but not Dean? Do you see the irony here?"
Don't get me wrong. Sam (and Dean) totally made the right call with Molly. She needed to let go and move on. But it's a lot easier to help some random ghost cross over than to let go of your brother who's skipping along the veil as if it were so much jump rope, wouldn't you say, Sammy?
Then in "Heart," we have Sam again questioning how it is that Dean can cap an innocent girl who has no idea she's evil, while letting Sam--who believes he will go darkside--to run around free. Why is Dean willing to save Sam and not Madison? Well, Sammy, same reason you wouldn't let the Reaper collect Dean at the hospital. It's a whole lot easier for Dean to protect you (he's got a lifetime of doing that) than to run the risk of letting someone else (in this case, a werewolf) wreck havoc on the neighborhood.
Now, I'm not saying this is right or wrong. It's natural to choose those you love over those for whom you don't have a particular affinity for beyond a pleasant "Yeah, they're a nice person." It's human nature, and it's loyalty. It just makes for an interesting comparison.
Also, the last scene in "Heart" continues to break mine. Dean, so willing to take this burden from Sam because it's a burden he's been carrying most of his life, and he knows it will be easier for him than for Sam. Dean already carries all sorts of guilt, what's a little more? And Sam, knowing he has to be the one to do it, because Madison, someone he cares about, asked him to help save her this way. And Dean, watching his brother leave the room, hearing him do the deed, waiting for Sam to return.
Oh, boys.