firts of all, as much as the season ending was totally contrived, i thought that at least it was well pulled off, although the plot devices and how easily the doctor was convinced to open the blast doors kind of hurt the narrative/plot quite a bit.  I was totally bummed Andrea didn't die.  She is an annoying character at best.  
 
Overall impression; the series is good, but it so far has been falling too much into my least favorite zombie movie problem, which is characters failing to understand that zombies cannot be reasoned with.    I had a big problem with the fact that they thought they were doing the characters who were infected during the attack on the campsite by letting them suffer and become zombies, especially Andrea, who I was so certain was going to get bitten because she wasn't able to think reasonably.  I understand emotional attachment is an important factor, but I would think at this point in the apocalypse, people would start to understand this sort of thing.
 
Favorite character so far is Glen.  I dislike the dynamic with Rick Shane and Lori, as it doesn't seem like Lori gives a shit about Rick, and seems content to shit all of Shane (which is then justified in the season finale when he tries to assault her, etc.  What a dick.)