pentaho 4.1.0 vs pentaho 4.8.2 version

Hi
Currently i am using pentaho 4.0 GA version.

I am trying to migrate to 4.8.2 GA version..i need more information regarding this two version

1. Repository details
2. Migration details
3. New features in PDI ,PRD ,PSW...

Can anyone give me clear idea about these two version..Its urgent requirement..


Thanks in advance