right, this is not specific to mac os x, but to maven 3.1.0
Try re running the build with maven 3.0.4, you won't reproduce the issue.
It appears that this section :
                    <plugin>
                                <groupId>org.codehaus.mojo</groupId>
                                <artifactId>build-helper-maven-plugin</artifactId>
                                <version>1.3</version>
                                <executions>
                                        <execution>
                                                <id>attach-artifacts</id>
                                                <phase>package</phase>
                                                <goals>
                                                        <goal>attach-artifact</goal>
                                                </goals>
                                                <configuration>
                                                        <artifacts>
                                                                <artifact>
                                                                        <file>kepler.target</file>
                                                                        <type>target</type>
                                                                        <classifier>kepler</classifier>
                                                                </artifact>
                                                                <artifact>
                                                                        <file>juno.target</file>
                                                                        <type>target</type>
                                                                        <classifier>juno</classifier>
                                                                </artifact>
                                                                <artifact>
                                                                        <file>indigo.target</file>
                                                                        <type>target</type>
                                                                        <classifier>indigo</classifier>
                                                                </artifact>
                                                        </artifacts>
                                                </configuration>
                                        </execution>
                                </executions>
                        </plugin>
makes the install plugin want to install all the targets in the local repo :
[INFO] --- maven-install-plugin:2.3.1:install (default-install) @ me.gladwell.eclipse.m2e.android ---
[INFO] Installing /Users/anthony/workspaces/m2e-android/me.gladwell.eclipse.m2e.android/target/me.gladwell.eclipse.m2e.android-1.0.0-SNAPSHOT.jar to /Users/anthony/.m2/repository/me/gladwell/eclipse/m2e/android/me.gladwell.eclipse.m2e.android/1.0.0-SNAPSHOT/me.gladwell.eclipse.m2e.android-1.0.0-SNAPSHOT.jar
[INFO] Installing /Users/anthony/workspaces/m2e-android/me.gladwell.eclipse.m2e.android/pom.xml to /Users/anthony/.m2/repository/me/gladwell/eclipse/m2e/android/me.gladwell.eclipse.m2e.android/1.0.0-SNAPSHOT/me.gladwell.eclipse.m2e.android-1.0.0-SNAPSHOT.pom
[INFO] Installing /Users/anthony/workspaces/m2e-android/me.gladwell.eclipse.m2e.android/target/p2content.xml to /Users/anthony/.m2/repository/me/gladwell/eclipse/m2e/android/me.gladwell.eclipse.m2e.android/1.0.0-SNAPSHOT/me.gladwell.eclipse.m2e.android-1.0.0-SNAPSHOT-p2metadata.xml
[INFO] Installing /Users/anthony/workspaces/m2e-android/me.gladwell.eclipse.m2e.android/target/p2artifacts.xml to /Users/anthony/.m2/repository/me/gladwell/eclipse/m2e/android/me.gladwell.eclipse.m2e.android/1.0.0-SNAPSHOT/me.gladwell.eclipse.m2e.android-1.0.0-SNAPSHOT-p2artifacts.xml
[INFO] Installing /Users/anthony/workspaces/m2e-android/me.gladwell.eclipse.m2e.android/kepler.target to /Users/anthony/.m2/repository/me/gladwell/eclipse/m2e/android/me.gladwell.eclipse.m2e.android/1.0.0-SNAPSHOT/me.gladwell.eclipse.m2e.android-1.0.0-SNAPSHOT-kepler.target
Maven 3.0.4 is ok with the files not being there (the target files are only in the root of the project, not anywhere else) : it happily ignores the copy issue; but maven 3.1.0 does not tolerate this anymore, hence the : 
[ERROR] Failed to execute goal org.apache.maven.plugins:maven
-install-plugin:2.3.1:install (default-install) on project me.gladwell.eclipse.m2e.android: Failed to install artifact me.gladwell.eclipse.m2e.android:me.gladwell.eclipse.m2e.android:target:kepler:1.0.0-SNAPSHOT: /Users/ricardogladwell/Projects/m2e-android/me.gladwell.eclipse.m2e.android/kepler.target (No such file or directory) -> [Help 1]
Anthony