Some more info that might be useful.
1) unless your project is an actual groovy project the groovy nature and groovy libraries are only added to it as part of DSL support.
2) However, when you disable DSL support the Groovy nature and library entries probably will not be removed for a project that has dependency management enabled. This is because the tools don't really have a way of knowing right now that they are not needed. I've been thinking about a way to fix that, but haven't come up with a good solution yet.
To avoid the groovy nature and libs getting added try cleaning out all the Eclipse configuration from your project then import it again making sure the 'enable DSL' is not selected on initial import.
Alternatively, you can manually remove the library entry as Andrew suggested and, I believe, if DSL support is disabled, it should not come back the next time you refresh dependencies.
Kris De Volder -- SpringSource