A great, non NDA breaking round up of some of what we can talk about in iOS 6 by Keith Harrison.
However Chuck Toporek has a better suggestion. If you are a member of the iOS developer programme then do yourself a favour and log in to check out the full juicy details with the release notes and API diffs. It's going to be a great release.
Video recorded at this week's Spotify developer meetup with talks from Mike Ash, Daniel Kennett and Joachim Bengtsson. Mike's talk is predictably impressive (see "Circle" below) but there is great content in them all. I was unable to get a ticket to the event this week so am really glad they put the video out so quickly.