WebmasterWorld members are reporting that Google is being stricter in accepting new publishers for Google AdSense. Your site must adhere to specific guidelines to be included. Rejection reasons include not owning the TLD of the site you are applying for Google AdSense, an active domain (6+ months of age), including personal information that is accurate, and applying from a website with original content.
Good news? Absolutely. Nobody wants to see AdSense on domains that have poor quality. But some suggest that Google should review all sites with AdSense -- yes, manually. Of course, that won't necessarily cure all issues, because I could be approved on mysite.com and still publish my ads to myothersite.com, but it can help.
In any event, most advertisers are happy that Google is finally being a little more stringent about the quality and age of the sites that advertisements are being pushed out to.
Forum discussion continues at WebmasterWorld.