There seems to be a major bug in Google Webmaster Tools where Google is telling virtually all webmasters that their sites are not indexed in Google. For example, I am personally getting the following message for all my sites:

Yes, that reads:

Hmm, but this site is indexed in Google:

So, I would not worry, it just seems to be a display issue in Google Webmaster Tools. As you can imagine, there is a lot of forum noise about the issue.

Forum discussion at DigitalPoint Forums, HighRankings Forum and Google Groups.