I've just sent something I've been working on to Thomas so he can hopefully post it up somewhere - read the rest of the post as if you have a link here and I'll update when I get the link.

In case you don't want to start from scratch. Unfortunately I haven't been able to get it to run in a "real" Eclipse instance (using the Export wizard from the plugin.xml overview page), when you click file->new->project, other->JBoss PortletProject, you will get an error message

The selected wizard could not be started......

If you hit details you'll see that it can't find the class org.eclipse.ui.wizards.newresource.BasicNewResourceWizard - which is in the plugin org.eclipse.ui, which is on the dependency list.
However, it works in a runtime Eclipse, so if you start a new eclipse with Testing->Launch an Eclipse Application on the overview page of plugin.xml, it'll work fine and you can see what I've done so far. Maybe someone who's done more plugin work than I have (which won't be hard!) can figure out what I've missed.

It's still a bit rough - I wanted to tidy it a bit before releasing, but since this forum is up I figured it would be better to get a bit embarassed about untidy code than let someone do a bunch of work that has been done already - and as I mentioned above the "new JBoss portlet project" is still under the "other" category, not a special JBoss or Portlet category, but the functionality is there to get some basic information about your portlet application and create some skeleton code, build files and xml descriptors. I'd like to extend it so you can add a new portlet to the portlet application and it would update the descriptors accordingly, and things like for a new portlet creation you can specify some configuration parameters which would then be correctly described in the descriptors.

Hopefully it'll be a good kickstart for this project

Cheers,
KEv.