In the Editor pane hovering the mouse for a while above a method, field or class should display a javadoc tooltip. 
There are two reasons:
1. Reading and understanding code is extremely dependent on understanding what happens inside the functions, or meaning
of the class or field. 
2. Quickcheck for written javadoc. looking at the correctly formatted tooltip of an javadoc can reveal errors in complex
javadoc comments. For instance javadoc including code examples, or the inheritance of javadoc may not always be clear at
first sight.

(Testing and using Netbeans after using Eclipse makes on miss this feature.)