First, it doubles the time an aggrieved party can recover an object of "historical, interpretive,scientific, cultural, or artistic significance" that has been stolen or taken by fraud or duress
Second, the law enacts the "actual discovery" rule. That means that the six year clock only starts to run once the original owner actually discovers the wherabouts of the cultural object.
Third, the law is retrospective. The legislature specifically stated that the law "shall apply to all pending and future actions commenced on or before December 31, 2017, including any actions dismissed based on the expiration of statutes of limitation in effect prior to the date of enactment of this statute if the judgment in that action is not yet final or if the time for filing an appeal from a decision on that action has not
expired, provided that the action concerns a work of fine art that was taken within 100 years prior to the date of enactment of this statute." There is no doubt then that the new law may impact Marei Von Saher's effort to move forward on her claim to recover Lucas Cranach the Elder's diptych "Adam and Eve" from the Norton Simon Museum, originally looted by the Nazis.
Read the law at http://leginfo.ca.gov/pub/09-10/bill/asm/ab_2751-2800/ab_2765_bill_20100930_chaptered.html