So, Meredith survives. Grey's Anatomy pushed Meredith to the brink and she decided to return from "limbo" and come back to life after her friends had pretty well written her off. But, Meredith did not make her decision based on her belief in God or religion, but rather was encouraged by the nearly "dead" to choose life. Limbo is neither heaven nor hell. It is the ultimate place in-between, a no-place where resolution, change, even death, are not really possible. Meredith must leave limbo so that the nearly dead whom she meets (former characters in the show) can make the transition to another place that no one really defines but we assume is some kind of heaven.
It turns our that Meredith had 'sort' of committed suicide by not fighting to survive the cold waters of Puget Sound. She had given up when she might have been able to swim to safety. The show revolves around her slow discovery that her life actually means something to her. And in the final moments before her ascent to the living, she meets her mother who has just collapsed and died.
What can one make of all this death, of a show that constantly places death into the forefront of everyone's experience? After all, Izzie lost the love of her life. George lost his father. And, if it isn't someone dying, then it is about other types of loss. The characters are in a perpetual storm with bombs, ferry disasters and personal pain. There is never any pure and simple clarity (even Derek's love for Meredith is tinged with contradiction and varying degrees of regret) to their everyday lives.
The limbo that Meredith finds herself in is actually a metaphor for television in general. Most of the current popular shows (aside from American Idol) are somewhere in between plot resolution and simple failure. Lost for example never ends! There is no resolution in sight to the conflict between isolation and madness. But, "Lost" is limbo in the most complete sense as developed by Dante— an island or series of islands with no people and no links to the outside world. The interior world of the characters becomes a playground of past and present connections. The islands become the unconscious and we are witnesses to the dreams and nightmares of the characters.
Extend the metaphor further and you realize that the United States is in limbo — unsure of its direction, wandering in the nightmare of a war, troubled by its weakness and assaulted from all sides — neither heaven nor hell!
Grey's Anatomy ends with the characters who are in love reaffirming their attachment to each other, but in the context of an overwhelming sense of pain. Hope it seems is at the faint edges of a journey that seems to have no destination.