Call it the Google+ effect. After July 31, Google is going to delete all private profiles. There’s no way to opt-out. If you want to keep your profile, you have to make at least your name and gender public.
Don’t worry about Google deleting your profile. It won’t delete your Google account or Gmail account. It just gets rid of the profile that you used for social services like Google Buzz or the sharing feature of Google Reader.
Of course, you could always convert your old Google Profile to a Google Plus account and join in the fun of exploring a new social network. [Search Engine Land]