Eclipse 2.1 - New and Noteworthy

User customizable key bindings
Editor navigation history
Improved default text editor
Improved editor linking behavior
Better UI for editor / view synchronization
Ant view/editor
External tools & launch configurations
More flexible project layouts

Java Editor :-
Sticky hovers
Prominent status indication
Find in file
More Quick Fixes/Quick Assist
Hyper-linked Java code

Java Debugger

Refactoring

JUnit integration

Plug-in Development Environment