There are a few early reports that some Google AdWords advertisers received what is called a Google Slap, basically a spike in their minimum CPCs due to Google's quality score.
A WebmasterWorld thread has two confirmed reports over the weekend that their cost-per-click (CPC) prices have skyrocketed overnight. Here are quotes of the two reports:
Well, I got around 8,000 keywords with a bid of $10.00 today, which most where on $0.15 and $0.30.
We had exactly the same problem! On Fri 11th we got slapped hard by Google. Our bids which were normally 5c-10c cpc with a great QS jumped to $10 for a min bid. This was on a site that had been doing extremely well for the past few months then with no warning Bam!~
This site had a similar set up to what you described: lots of campaigns all leading to different landing pages for different products.
Have tried several things to revamp the campaigns but nothing seems to be working.
The first report comes from a very senior member with 1,524 posts and a join date of January 2005 at WebmasterWorld. Now, this could have impacted just a few people, but it seems like it might be more widespread. We will see if the thread takes off today, being Monday and all.
Note, this week, likely today or tomorrow, Yahoo's is changing how they handle minimum bids. They too will be having a quality score factor that can impact one's minimum bids. Soon to be labelled the Yahoo Slap, I guess. I have more details on that, over here.
Forum discussion at WebmasterWorld.