dependency plugin automatic version resolution

Hi,

I was reading
http://maven.apache.org/guides/introduction/introduction-to-plugin-resolution.html
and
https://cwiki.apache.org/confluence/display/MAVEN/Maven+3.x+Compatibility+Notes#Maven3.xCompatibilityNotes-AutomaticPluginVersionResolution

Based on that, I understood that if I call a plugin from CLI without a
version, maven will try to get the latest (and released for maven 3.x)
version available for the running maven.

I understand as well that some plugins are already bind in a certain
version阧?✥ phases.
http://maven.apache.org/ref/3.0.5/maven-core/lifecycles.html

What I don't understand is why dependency:tree is always running version
2.0 (for maven 2.1.0), version 2.1 (for maven 3.0.5) when I don't specify a
version. Maven 3.2.1 will run the latest version, 2.8.
You can see that even the latest version of the plugin requires only maven

http://svn.apache.org/viewvc/maven/plugins/tags/maven-dependency-plugin-2.8/pom.xml).
I've checked the metadata as well, it looks fine (
http://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-dependency-plugin/maven-metadata.xml).

What lead me to think that some other plugins have the versions "hardcoded"
in maven. Is that correct? Where can I get the list of those plugins?

Steps to test:

-DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false

I removed my maven settings.xml files before testing, so I don't think it's
something local.

Cheers,

Cintia Del Rio