Let me start off by admitting that I thoroughly enjoyed Spurlock's Super-size Me. But the jury is still out on 30 Days.
After completing the first season, it feels like we are beating a dead horse with this "30 days" thing. Some good content, but might be better presented under a different premise.
The first season was short lived at only 6 episodes, but I guess this is pretty standard in the TV world. About half of the six shows that aired were good enough to get me to sit through the other half, which were somewhere between boring and abysmal. The season finale was absolutely horrible. Disjointed and pointless.
Hopefully they get it together and make Season 2 a lot better. The potential is there.