The Bindings use MQeAttributeHndl as a base type for many differnet types of attributes. These types have been more tightly specified, for example getMessage calls take MQeFieldsAttrHndl.
The Bindings used a wrapper around the Java Enumeration classes. This has been replaced with a native MQeVector. The major change here is in terms of memory management. This is detailed in the Programming Reference/Examples/HTML reference guides.