If you are working with Java on OS X then you probably should be trying out SoyLatte. SoyLatte is a port of BSD Java for OS X, it is also part of the OpenJDK initiative. It can help you work around the many issues you'll likely have with the 1.6 Java SDK supported by Apple (I couldn't get Woodstox working with RelaxNG schema support).
First off download it. Then you'll probably want to install it somewhere (/usr/local/soylate-xxx should work). Then make sure you have a JAVA_HOME shell var pointing to this folder. Make sure also you add the bin folder to the path.
Getting Eclipse running on SoyLatte is cake. Open the preferences, select "Java > installed JREs", click the 'add' button select the 'MacOS X VM' option and next. You'll now want to point to the SoyLatte folder and finish things off. Select the SoyLatte JRE and close the preferences.
Last thing I'd like to point out. I use CXF to do web services, and found there was an issue with SoyLatte using JAXB 2.0 when I need JAXB 2.1. To solve this I just downloaded the jaxb-api-2.1.jar and jaxws-api-xx.jar and put them into the soylatte/jre/endorsed folder.