I haven't seen it, but my niece has and she says I should see it because it's really, really good. However, this is also a young woman who thinks Twilight is a romantic horror movie and Transformers 2 had a fascinating plot, so take that with a grain of salt.
From what she said, it does sound like something that might be interesting. There's apparently some sort of
Spoiler (mouseover to read):
that sparks the plot off, however, which is the main reason why I haven't watched it yet. It's a rare movie that handles something like that well and if that movie is a dark comedy? I think I'll wait until somebody whose taste in movies I trust a bit better recommends it.