Will iPhone App Update to new version will remove all the ratings? I plan to update my app with new features. If I publish a new version say V 1.0.1 then will I loose all my ratings from version 1.0.
Apple splits your App's ratings into two sections; "Current Version" and "All Versions".

The preference on the App Store is to display the "current version" ratings, however aggregated historical ratings and reviews are also available.