One of the running metaphors that Hamlet uses throughout the soliloquy is that of sleep as a symbol for death. This is made explicit when Hamlet mentions the "sleep of death," but it is used prior to this in more symbolic ways. This helps to bring out Hamlet's weariness and desire for simple peace. This desire is central to his character and to the soliloquy itself; it is his desire for peace and rest that drives him to contemplate suicide, but the fact that these things are far from guaranteed in the afterlife -- especially for one who commits suicide -- is enough to make the action unpalatable even in what he perceives as his extreme circumstances. There is also a sense of travel associated with death and the transition to the afterlife that appears in the soliloquy, from "shuffl[ing] off this mortal coil" to the "undiscover'd country" that is used as a stand-in for...

This makes suicide and even simply death more of an active pursuit than it might otherwise be thought, and adds an interesting layer of meaning to the soliloquy. One of Hamlet's major problems throughout the lay is his inability to act, and his indecisiveness. The struggle in this soliloquy is not between giving up or fighting, but between two different courses of action, and Hamlet finds himself yet again stuck in the decision making process.
Obviously, however, Hamlet does not kill himself during the speech. This does not show a clear decision, but rather an unwillingness to make one. He does seem to have a new resolve, however, having acknowledged what he takes as his cowardice in refusing to face the afterlife, he is resigned to facing his troubles in this life. In a strange way, this soliloquy sees Hamlet develop a more resolute self-doubt.