Now that SLF4J makes use of varargs in the source code, org.slf4j.helpers.NOPLogger should be aligned rather than still using arrays, which produces compiler warnings for me in Eclipse.

On a related point, there are also a few JavaDoc warnings; e.g. org.slf4j.Marker.contains(String name) does not declare a parameter named "other" (but this is used in the JavaDoc); org.slf4j.helpers.MessageFormatter.format(String, Object). I recommend configuring Eclipse (or any other static source code analyzer) to also warn about JavaDoc problems.