Howdy Eclipse committers! The committer representatives want to make sure that you are aware of the updated Trademark and Logo Usage Guidelines. As Mike mentioned, the big difference is that project names, acronyms and logos are recognized as Eclipse trademarks. If people recall the Mylar -> Mylyn transition, this was the primary reason for the rename.
To put it simply, the Eclipse Foundation takes a lot of pride in the cleanliness of the intellectual property within Eclipse. Trademarks are considered intellectual property, therefore as committers, we must ensure our project names and logos are clean. Plus, as committers, we can come up with cool and funny names like TPTP or COSMOS for our projects ;)