Earlier last month, Google launched “AdSense for Feeds” for anyone to use it. For existing FeedBurner users, Google had provided an email address (email@example.com) to contact Google to migrate your account, the email address has now been replaced by a form. Once the migration was done, Google informed all users to start burning AdSense for Feeds, and after a day or two, FeedBurner's new home allowed login. Google had informed that initially for first few days, people may found that the number of subscribers dropped to 0, which’ll be reflected correctly in few days time. But the most visible issue is that Google Blog Search stopped indexing this blog and many other blogs after migrating to the new FeedBurner. There are many other bugs related to this transition. Wish Google acknowledge and fixes.
Source:→ Google System