This section of the data sheet contains a list of possible updates that have occurred with the processor.  These revisions will include changes is speed specifications, temperature characteristics, device nomenclature, and often fixes to known silicon issues. 

The revision history is contained in the Data Sheet to provide specific device changes in detail which are often improvements in the operation of the device.  As new part numbers are released, a corresponding data sheet will be created and the revision history will provide details on how the device differs from other devices with different suffixes.