I agree with G-man
; if Daryl died, I would give serious consideration to whether I wanted to keep watching week after week. In a show this dark, there needs to be someone to really root for, to connect with, and for me, it's Daryl. While I certainly am interested in Rick, I care the most about Daryl. It happened gradually, perhaps because we don't know as much about Daryl as we do Rick. Perhaps it's because he doesn't seem to have any agenda and is just doing the best he can. There's no unnecessary angst with him; he just tries to get by the best he can, and in the process, has slowly, reluctantly come to the conclusion that he really does care about people. He is a good guy, although he knows it would be easier for him if he weren't. Of all of them, he is the most capable of surviving on his own, but chose to stay with the group. And the relationship with Merle is fascinating. We want Daryl to finally pull away from him and see the parallels between Daryl & Merle and Carol & her abusive husband.
All of this has been building slowly, subtly (well, as subtly as this show will allow) and the audience loves him for it. If Daryl is killed off, I suspect the audience share would drop noticeably.
IMHO, anyway. Your mileage may vary.