i get the impression woody allen has written this at a time in his life when he's looking back on a list of failed marriages and relationships and decided that he doesn't like them. marriages or relationships. this film is a bit of an exploration on how rubbish it can be to be in love, and how it will probably destroy you from the inside out in some way.
allen does heap a certain amount of guilt and blame upon himself though, i think he sees himself as the javier bardem character; at first impressions a gifted romantic with oceanic depth, but as you study him you find a manipulative ass who will happily cause long-term emotional damage to the women around him for a few nights of kinky passion. which is a shame.
it is also a shame that allen seems to have truly lost the control of his inimitable style, and it manifests itself in vicky cristina barcelona as a difficulty in giving the characters their own voice, instead making them all speak like a woody allen stand-up routine.
and as a little added bitterness to the pill, i just found the whole thing a little bit boring. certainly wasn't expecting that from a film that had scarlett johansson and penelope cruz snogging.