A WebmasterWorld thread has two advertisers claiming that Google AdWords is sending them less traffic then they are accustomed to.
Here is one complaint from one AdWords advertiser:
I have been running this Adwords account for 4 years and since two months the amount of traffic from this account (2000+ keywords) has been steadily declining. The Quality Score and AVG position remain unchanged. I have been changing the keywords bids here and there but mostly bidding up.
Another advertisers had a similar complaint, but netmeg suggested they take look at the "impression share report."
Take a look at the impression share report (campaign report with the IS stuff checked) to see how often your ads are running as a percentage of how often they could be running.
Are you experiencing a a decline in your AdWords traffic?
Forum discussion at WebmasterWorld.