Matt Cutts has come up with a good idea; a video to shadow every conference presentation he's doing. This means if you live in Scotland and can't justify going to pubCon because it's primarily a drinking fest then you can still see some of the keynotes.
Just a few minutes into the video - around the 2:10 mark - we encounter Android. He teases us and announces that Google's launched an OS. However, then goes on to say that Android is primarily intended for mobile phones. Quickly after that he appends 'at first' while discussing the role as a mobile phone OS.
I don't think this will surprise anyone - however, this seems like rather unusual unofficial official confirmation.