When I start Eclipse and add it to the Unity Launcher, I get a ? symbol as shown in the screen shot instead of the Eclipse icon. The same happens for some other applications also and I am not able to differentiate between applications in the Unity Launcher. Also, is there a UI for easily adding launchers and quicklists? Also, how do I change the order of the icons in the Launcher?
Try to add StartupWMClass=Eclipse
line to the eclipse.desktop file.
To detect application's _WM_CLASS_ use: xprop | grep CLASS
After the plass appears, just click on your application.
Read this for further information.