As noted in the Eclipse Wiki, ICU4J was adopted by Eclipse 3.2. ICU4J provides “more comprehensive support for Unicode, software globalization, and internationalization” than the standard
java.text libraries, but comes at a cost. ~3MB to be inexact.
The functionality provided by ICU4J is great to have… if you need it. But one of the problems with this is that 3MB can be a lot when you’re building an RCP application and you don’t particularly care if all that software globalization stuff works exactly right. You can’t just remove the plug-in since it’s required by the platform code; but you can replace it with a much smaller plug-in (~100KB) that calls through to the
java.text classes. You can download this from the same place you downloaded your RCP target (here for Eclipse 3.2).