Sorry, yes.
When run, it shows the usual SLF4J warning about not finding an implementation:
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
And then the runner doesn't log anything about its operations. I tried the same command line, changing only the jar used, and the 1.4.8 version printed out processing information (like: "processing group: groupName.js"), while 1.4.9 didn't print out anything (apart from the SLF4J warning above).
My command line was (parameters edited):
java -jar wro4j-runner-1.4.9-jar-with-dependencies.jar --wroFile wro.xml --contextFolder ./input --targetGroups all --destinationFolder ./output -c yuiJsMin -m
A.