No. The plugin uses maven dependency management to get the required libraries and native components depending on your operating system
Simply define a dependencies on ''com.google.gwt:gwt-user'' with the expected version, the plugin will detect this and download the required SDK artifacts.
This plugin, being part of the Mojo Project, can benefict for a large community of maven developers. Its async interface generation feature is AFAIK not supported by other plugins.
GWT guys don't use Maven by themselves but are interested by our work to provide community support. They helped us to make the plugin work with the GWT SDK release candidates.
gwt-dev JAR includes many libraries, including some Apache commons-* that you may use in your project with more recent version. Don't define gwt-dev as a dependency, the plugin will resolve it when necessary for you based on your gwt-user version.