Little League has released new rule updates for the 2012 regular season and 2012 International Tournament. See http://www.littleleague.org/media/newsarchive/2011/Sep-Dec/Bulletin-SignificantPolicyRuleRegulationChanges2012.htm for the complete list. Most of the changes are clarifications, but there are a few significant playing rule changes.
As announced a few weeks ago, using an illegal bat can now result in a out for the batter. The revised bat rules announced a few weeks ago are included as well.
Also, newly announced, in the Majors division there is now a dropped third strike rule, although local leagues may opt out during the regular season. There will be a dropped third strike rule for 10-11 Year Olds, 11-12 Year Olds, and all higher levels during the tournament.