A number of people are reporting that Google has sent a survey to select AdSense publishers. On the DigitalPoint Forums, members discuss the survey and are overall pretty satisfied that they were able to participate and give insights about how to improve the service.
The only concerns voiced was that a select few individuals thought that it would have been better to have more opportunity to provide detailed written answers.
This is very similar to the surveys that were dispensed a little over a year ago. You can opt in for future surveys and mailings from the Google AdSense team by accessing your email preferences. As an incentive, participants are entered into a draw for $1,000.
Forum discussion continues at DigitalPoint Forums.