次のようにmaven-dependency-plugin を使用できます。
<project>
[...]
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.6</version>
<executions>
<execution>
<id>unpack</id>
<phase>package</phase>
<goals>
<goal>unpack</goal>
</goals>
<configuration>
<artifactItems>
<artifactItem>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<type>jar</type>
<overWrite>false</overWrite>
<outputDirectory>${project.build.directory}/alternateLocation</outputDirectory>
</artifactItem>
</artifactItems>
...
<overWriteReleases>false</overWriteReleases>
<overWriteSnapshots>true</overWriteSnapshots>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
[...]
</project>
または、次のようにtruezip-maven-pluginを使用できます。
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>truezip-maven-plugin</artifactId>
<version>1.1</version>
<executions>
<execution>
<id>unpack</id>
<goals>
<goal>cp</goal>
</goals>
<phase>ThePhaseYouLike</phase>
<configuration>
<from>${project.build.directory}/WhatEveryArchive.zip</from>
<to>${project.build.directory}</to>
</configuration>
</execution>
</executions>
</plugin>