The update is currently being pushed to users both over-the-air and through the Samsung Kies desktop application, and weighs 239MB.

Unfortunately, Samsung did not offer a specific changelog for the update, but all the features and enhancements that ICS was made available with should be included in the package.
Galaxy R users will be able to take advantage of Face Unlock, various UI changes, widgets enhancements, better notifications, and a series of performance improvements as well.
Users can manually check to see whether the update was released for their devices through heading to Settings -> About Phone -> Software Update on their phones.
Source

Unfortunately, Samsung did not offer a specific changelog for the update, but all the features and enhancements that ICS was made available with should be included in the package.
Galaxy R users will be able to take advantage of Face Unlock, various UI changes, widgets enhancements, better notifications, and a series of performance improvements as well.
Users can manually check to see whether the update was released for their devices through heading to Settings -> About Phone -> Software Update on their phones.
Source

