Presumably they hadn't yet decided when they filmed it, they want to see what the audience's reaction is and decide later. Which is really lame.
I liked the series, but didn't think much of the last episode. Everyone in the group, including the experienced tracker Daryl, was out-maneuvered by...
I enjoyed all of them, but that's partly because I didn't have to wait between episodes (and the eastenders endings). If you found S2 incredibly dull, perhaps it's just not for you, so find something else.