Cassius, a slippery, sly, scheming man, that because of his past, chooses someone else to do his dirty work for him. This is reflected in his cowardly, timely death.

He commits suicide alone. It is not an honorary death. It is a cowards death. He does this to end his sadness that he knows he and Brutus will lose and to exit quickly without facing the after-effects. The line, `Caesar, thou art revenged, even with the sword that killed thee,' Cassius is realising that Caesar's murder was done to no advantage, and that it shouldn't have happened.

Compare this to Brutus' death, which has come about because he feels his time is up. This is more to do with the fact that he saw the ghost of Caesar...