I just replaced my complete Mac setup from an iMac + Macbook Air to a Retina Macbook Pro + a Thunderbolt Display, which is a reallllly great combination. Unfortunately there are some apps that don’t support the retina mode yet. Eclipse is one of them.
If you have a retina Macbook Pro and want to use Eclipse or any Eclipse based application it will look quite ugly with current versions. A workaround (at least for the pixelated fonts) is to open the eclipse.app bundle and add this key to the Contents/Info.plist: NSHighResolutionCapable and set it to YES. (Easiest to do with a plist editor like the one included in Apples developer tools)
Because Mac OS seems to cache the info.plists you may have to logout and login again, or alternatively copy the app bundle and insert it again at the same location. Then delete the old app bundle.
This may also work for other applications where the “Open in Low Resolution” checkbox is greyed out if you right-click on an app and select “get info”. After adding this key to the info.plist of the app, the “Open in Low Resolution” checkbox will be accessible.