I've noted this on the dev@ ML, but I'll add a short comment here as well.
I think this is a great idea, and I like the approach of the patch. However, I'd like to see us take it a little further before we consider releasing a version of Maven with this patch in place. I'd like to have an option to trigger plugin/execution suppression from somewhere in the POM, not just via CLI option. This allows us to say, "My build uses the jar packaging, but I never want the X plugin to run."
To me, this is important because it means we don't have to worry about users getting the right CLI options in place to run a build (or, more importantly, a release). In many cases, failing to use the suppressing CLI option may break the build, but in others it may lead to incorrect build results being released for public consumption. Also, in cases where it's important that users can rebuild the project from source (as in cases where ASF votes are taken), requiring a CLI option to produce a correct build adds a new layer of build complexity. It takes us away from the common vocabulary that makes Maven so effective, and back toward something more like Ant, where you have to know the correct incantation to produce a build.
I hope this patch is applied, but I think we need to spend a little more time focusing on how to codify these suppressions in the POM before releasing a Maven version with this patch in place.