Seems that the issue "Log configuration problem" (ID: 3479730) should be reopened.
I can confirm that the logback conflicting problem exists in Redmine-Mylyn Connector 0.3.7.
Steps to reproduce:
1. install eclipse-java-indigo-SR2-win32-x86_64 (which with m2e 1.0.SR2 bundled)
2. create a maven project (File / New / Other... / Maven / Maven Project / Next > / Create a simple project / Next > / Fill in Group Id and Artifact Id, and press Finish)
3. in Console view, open "Maven console"
4. open the context menu of newly created maven project / Maven / Update Project Configuration... / OK, there show be something showed up in the "Maven Console"
5. install "Redmine-Mylyn Connector" form update site, restart ecplise
6*. redo step 3, 4, nothing showed up in the "Maven Console"
7. uninstall "Redmine-Mylyn Connector" and redo step 3. 4... messages come back...
I copied contents of m2e logback.xml into the mylyn redmine connector one,
Maven console seems ok now, expect that in the first time, one folder named "org.eclipse.m2e.log.dir_IS_UNDEFINED" will be created in the eclipse folder.