Normally, I would not point to a thread that discusses rumors that I know are misguided. But at a thread at WebmasterWorld the official AdWordsAdvisor from Google replies to the speculation that Google uses data from Google Analytics (conversion data) to determine the price a keyword should cost. Here is AdWordsAdvisor's response;
This is a theory that seems to have acquired an (inaccurate) ring of truth through repetition - and I'd like to comment in as straightforward a way as possible:
AdWords does not currently (and has no plans to) use any information from Analytics or Google conversion tracking to set minimum CPCs.
Forum discussion at WebmasterWorld.