This page will track progress on building Eclipse RCP and applications based on RCP using Maven 2.
Building Eclipse RCP
The http://mojo.codehaus.org/pde-maven-plugin/ pde-maven-plugin provides maven binding to the PDE Ant build files used to run Eclipse builds in headless mode. With the patch available at http://jira.codehaus.org/browse/MOJO-569 this mojo now supports product builds (i.e. complete RCP applications)
It is by no means an ideal way of building the application. It is reliant on configuring variables in the mojo to locate an Eclipse installation and it relies on the Ant build instead of doing a "better" job at building bundles (the Ant task are very inefficient).
Using this mojo I (Bae) am able to build our companies Eclipse RCP application via Maven.
The next step is to get Continuum 1.1 working so that this can be built continuous when project dependencies change.
You will also want to read up on the Eclipse Plugin to setup your Maven environment for full automation.