A word of caution for anyone switching to Java 8 (which is now officially released by Sun).
Issues I have found so far:
Eclipse
The previous version of Kepler Eclipse runs with Java 8, but it only understands compliance levels up to Java 7.
The current version of Eclipse (Luna) does have Java 8 support and it is also possible to make Kepler compliant, see:
Installing Java 8 Support in Eclipse Kepler
Maven Plugins
The Cobertura code coverage plugin does not support Java 8 code and will fail unless you use the Maven compiler plugin to set the compatibility level to be Java 7. JaCoCo does appear to work with Java 8.
Findbugs is not yet compatible with Java 8 and will fail. However the next release of Findbugs (3.0.0) should have support.