Had potential (but a ridiculous ending)
I must say, this movie wasn't that bad. For the most part, I liked it. It was gloomy, depressing, and eerie. The zombies were actually pretty scary. Everything was going good, until...the end. Wow. What a way to spoil a plot that had potential.
After what Olivia did to Ann, there's no reason why Ann should've saved her life, and let the guy she loved, Chris, get killed. There's no excuse. Now, some people might interpret her actions as trying to do the righteous and noble thing, unlike Olivia. An attempt to be the better person. And another way to interpret the ending, is that Ann viewed Olivia as a daughter, seeing that she lost her own, and didn't have it in her to let Olivia die. But still...Olivia betrayed her. She basically tried to kill Ann. So with that said, I don't find the ending to be at all satisfying or logical.
During the last scene, as Ann was driving away with Olivia; I was waiting for her to pull over and kill Olivia. That would've made more sense, and it would've made a better ending...in my opinion. Almost any ending would've been better than the one that was used.