Official 2013 regulation changes have been published, as I'm sure many of you have heard.
Some interesting ones from: http://www.fia.com/news/world-motor-sport-council-2012
More stringent front wing deflection tests have been introduced.
For safety reasons, use of the DRS during practice will now only be allowed in the place(s) it will be used on the track in the race.
Deletion of the ‘force majeure’ allowance when a car stops on the track in qualifying. The FIA will determine how much fuel the car would have used to get back to the pits and add it to the one litre sample minimum.
The team personnel curfew will be extended from six to eight hours on Thursday night and only two exceptions will be allowed during a season (formerly four).
Perhaps it was a typo but it's interesting that the DRS restriction doesn't mention qualifying.
BTW, the force majeure rule change was mentioned in various articles a few weeks ago but now it's official. (Example: http://www.autosport.com/news/report.php/id/104256