Today we have released Xtext and Xtend 2.4.1 with a number of bugfixes.
Important fixes were incorporated for Maven users, in the Xbase type validation and for Xtext languages that are used in RCP applications. Furthermore, Xtext is now compatible to all Guava versions since 10.x. For a detailled overview, check out the release notes.
To upgrade just choose Help -> Check For Updates in Eclipse.