No new rule has been put, it's more a rearrange of certain articles, so that the .is domain rules will better reflect the new .is domain law set by The Alþingi (the Icelandic Parliament) one year ago. Some wording is different, and the construction (new numbering of the Articles) has been changed. The only important change is for the Registry itself, e.g. neither the Registry nor its employees can be prosecuted when executing an order from Icelandic Courts or Law Enforcement regarding closure of a domain. Also ISNIC now has more warrants regarding domain closure (some would say this is bad) as can be seen in Chapter 3. These warrants were there before, but have now been put in stronger words. The domain holder (the registrant) is like before responsible for registering correct contact information, and that the usage of the domain is according to Icelandic law (Chapter 3). See updated .is Domain Rules in English.
ISNIC's Security & Legal Department.