m2e 1.5.0 requires Eclipse Luna. It will not work with Kepler or Indigo. (thanks to @HDave for the link)
So you have to use an older version of m2e under Kepler.
During installation, uncheck “Show only the latest versions of available software”. Then only check the 1.4.1 version or lower version in the candidate list. It doesn’t require the Guava dependency.