Google quietly announced on Google+ that they've updated how the Google AdWords reporting shows the Quality Score for your keywords.
Google made it clear that this does not and will not directly impact your ads, their rankings or CPCs. This is just a reporting change on the front end and doesn't impact the ranking algorithm of your AdWords ads.
Google said the most visible change advertisers may see is that new ads with no impressions will default to a quality score of 6 and then once Google has data, the score will be updated in "about a day or so later."
Here is the Google post:
Starting today, we will be updating how we report 1-10 Quality Scores for keywords [https://goo.gl/c4Oi7]. This update only affects reporting. There is no change to ad serving such as how auction-time quality signals affect Ad Rank and CPC. The most significant part of the change is that keywords without traffic will now, by default, receive a score of 6, and Average for the three components of Quality Score. Once keywords gather enough impressions, scores will update about a day or so later.Behind the scenes, this change will allow us to simplify some of our core systems, letting us focus our attention on improving reporting accuracy for keywords with traffic.
So if you see changes in your quality score, you should be safe and not have to worry.
Forum discussion at Google+.
