With it, users get out of the box:
Bundling of the Eclipse Color Theme plugin helps in keeping colors consistent among all editors, and LiClipse applies the color theme chosen to other parts of the IDE, allowing for dark themes that are kind to your eyes.
LiClipse supports many languages out of the box:
All those languages feature syntax highlighting, template completion, outline, select/deselect scope, comment/uncomment, auto-indent, linked edition, multi-edition, among others.
As a note, some editors have improved support:
The HTML editor has advanced context-based code-completion.
At this point, the major improvement is multi-edition supporting all editors (such as PyDev, JDT, etc).
See: Multi-Edition Video for details
Besides the multi-edition (which can be triggered in a Ctrl+K search or with the mouse with Ctrl+Alt+Mouse Click), the rectangular edit is also improved to be triggered with Alt+Click (and stopped with escape).
Eclipse has a myriad of useful plugins, and LiClipse bundles some which are considered to be useful regardless of which language you're dealing with: Workspace Mechanic, Eclipse Color Theme, StartExplorer, AnyEdit and PyDev (note that PyDev does not follow the rule of being useful for everyone as the other plugins, but LiClipse itself reuses parts of the PyDev codebase).