I think icons make sense and in general terms improve software usability if used properly. This applies to Eclipse as well. If you happen to use the context menu a lot, say for committing things to Git, you might be used to this:
No image icons in Eclipse
Note the plain context menu, which does not show any icons. Contrast this with this:
Image icons show in the context menu et. al.
Yay, icons show up 
For those of you who wonder how to enable icons in Eclipse, here is how you can do this (assumes Fedora 15 and Gnome 3).
$ sudo yum install gnome-tweak-tool $ gnome-tweak-tool
Then go to “Interface” and turn on “Menus Have Icons”. It should look like this:
Gnome tweak tool with menu icons turned on
