I have some rather large campaigns that on Nov 22 went to 0 (impressions and clicks). I would understand if i were penalized for low quality score, but on the content network only campaigns you can't see a quality score. Imo I really think this is a glitch for content network only campaigns that I am experiencing. Before this happened I had been seeing the too many keywords message when the only changes I had made in a week was moving (cut & paste in adwords editor) 4 or so adgroups to a diff campaign.
We all are having this problem, Google is not showing low cost bids as a rule of thumb. And with the downturn, their revenues are also down. They are setting an artificial starting point for bids now that will usually be above what you are willing to pay.