The full list of the 2011 rules changes are on the attached link

http://www.randa.org/en/Rules-and-Amateur-Status/New-Rules-2012.aspx#ooid=FmdzZ3MjqQ-TqEw-LIypcslRL_NEIoq_,NvNXB3MjpZvsCcDVFr9DMxEc-V5NFtiP

Summary:

Addressing the Ball

The Definition is amended so that a player has addressed the ball simply by grounding his club immediately in front of or behind the ball, regardless of whether or not he has taken his stance. Therefore, the Rules generally no longer provide for a player addressing the ball in a hazard. (See also related change to Rule 18-2b)

Rules
Rule 1-2. Exerting Influence on Movement of Ball or Altering Physical Conditions
The Rule is amended to establish more clearly that, if a player intentionally takes an action to influence the movement of a ball or to alter physical conditions affecting the playing of a hole in a way that is not permitted by the Rules, Rule 1-2 applies only when the action is not already covered in another Rule. For example, a player improving the lie of his ball is in breach of Rule 13-2 and therefore that Rule would apply, whereas a player intentionally improving the lie of a fellow-competitor’s ball is not a situation covered by Rule 13-2 and, therefore, is governed by Rule 1-2.
Rule 6-3a. Time of Starting
Rule 6-3a is amended to provide that the penalty for starting late, but within five minutes of the starting time, is reduced from disqualification to loss of the first hole in match play or two strokes at the first hole in stroke play. Previously this penalty reduction could be introduced as a condition of competition.
Rule 13-4. Ball in Hazard; Prohibited Actions
Exception 2 to Rule 13-4 is amended to permit a player to smooth sand or soil in a hazard at any time, including before playing from that hazard, provided it is for the sole purpose of caring for the course and Rule 13-2 is not breached.