I've only got two more eps ofseason five to go, I just watched the episode where Omar gets taken out by Kenard.
It's important that it's Kenard who did it - if you look back at season three, after the shootout at the stashhouse, it's Kenard who's playing with the other kids at the crime scene pretending that he's Omar ("I wanna be Omar, I wanna be Omar!")
And the fact that the death was so jolting was important - it was not grand or epic, it was a simple, rough death. It's symbolic of how just because Omar had come to believe he was larger than life, and how many of the things he had done may have been, in the end The Game caught up to him just like it catches up to everyone. Even Prop Joe, though he lasted a lot longer than most due to his intelligence and cool head.
Like McNulty said, "You start telling the story, and you think you're the hero, but by the time you get to the end of it..."