There is nothing released yet to do this... still might come in the future, but the way to do this now will be to import the XIN/DDB using the SS4 product, then upgrade that DGNLIB. This would be specifically for Feature Styles from an XIN or Items from a DDB. The command preferences stored in the XIN (like the annotation preferences mentioned above) will not mapped because the commands and workflows are so different between the products.
