Well doesn't every show have to have a point? what would be the point of us never knowing the identity of the killer? It would mean there being two serial killers at large for season two, thus knackering up the rest of the series.
Then again, it's all personal choice. I have no doubt that this show will be good, but I just have a niggling feeling that it wont be 'great'. I hope it proves me wrong, I love the era it is set and I want to see the show last.