This is probably one of the most informative videos I have seen so far, covering quite a few topics and features I haven't seen explained as well in other videos.
http://phandroid.com/2012/05/08/samsung-galaxy-s3-first-look-ctia-2012/
http://phandroid.com/2012/05/08/samsung-galaxy-s3-first-look-ctia-2012/