Well, not my site, but EliteWeb, received an email from Google, which basically asked EliteWeb to allow Google to index the site. EliteWeb said "I received an email from someone at google telling me the benefits of allowing the google spider to index my site. The site in question has a robots.txt file disallowing all search engines."
Moderator DaveN, said that he also received an email like that some time ago. With DaveN, his site was banned, he then disallowed Google from going to the site, Google sent a reinclusion request to DaveN for the site and he removed the no index. Then Google came back, indexed it, ranked it, and then banned it again 3 months later.
The question is, what would trigger a Reinclusion Request Directly from Google. Seems very unlike them.
Forum thread at WebmasterWorld.