GWT uses an embedded Jetty server. It is used at the beginning of the development of an application. During the prototype phase.
Personally, I used it for about a year, until we got the need to use JMS.
And since Jetty is not a Java EE server – it does not implement the JMS API – it was time to say goodbye to Jetty and use the application server that is used in production : Jonas.
There is not much info about the configuration to use in order to launch the hosted mode with a server different from Jetty. I found that the official website of the gwt-maven-plugin lacks information in that area.

I spent a few hours finding out the correct configuration for that. So here is how to do it :
1) Start Jonas
2) Deploy the application (EAR or WAR)
3) Run the goal gwt:run

And the configuration for the gwt-maven-plugin plugin is the following :

<plugins>
  <plugin>
	<groupId>org.codehaus.mojo</groupId>
	<artifactId>gwt-maven-plugin</artifactId>		
					
	<!-- Old configuration, to run the hosted mode with JETTY. -->
	<!-- 
		<configuration>
		<runTarget>identify.html</runTarget>
		<hostedWebapp>${project.build.directory}/${project.build.finalName}</hostedWebapp>
		<modules>
			<module>${project.groupId}.foo.bla.MainApplication</module>
			<module>${project.groupId}.foo.bla.SecondEntry</module>
		</modules>
		<copyWebapp>true</copyWebapp>										
		<extraJvmArgs>-XX:MaxPermSize=512M  -Xms512M -Xmx1024M </extraJvmArgs>
	</configuration>
	 -->
	
	<!-- New configuration, to run the hosted mode with JONAS -->
	<configuration>					
		<modules>
			<module>${project.groupId}.foo.bla.MainApplication</module>
			<module>${project.groupId}.foo.bla.SecondEntry</module>
		</modules>					
		<extraJvmArgs>-XX:MaxPermSize=512M  -Xms512M -Xmx1024M </extraJvmArgs>
		
		<webappDirectory>${project.build.directory}/${project.build.finalName}</webappDirectory> 
		<runTarget>http://localhost:9000/app-context/main.html</runTarget> 
		<copyWebapp>false</copyWebapp> 
		<!--  do not start JETTY -->
		<noServer>true</noServer>
		<!-- the folder where the exploded WAR is located, inside Jonas -->
		 <!--  Constant path if jonas.development=false in conf/jonas.properties --> 					
		<hostedWebapp>${env.JONAS_BASE}\work\webapps\jonas\ear\myapp-ear-SNAPSHOT.ear\${project.build.finalName}.war</hostedWebapp>
		<bindAddress>localhost</bindAddress>   <!--  other possible value : 0.0.0.0 -->
		<logLevel>INFO</logLevel> 
		<style>OBF</style> 			
	</configuration>
	<executions>
		<execution>
			<id>gwtcompile</id>
			<phase>prepare-package</phase>
			<goals>
				<goal>compile</goal>
			</goals>
		</execution>
	</executions>
   </plugin>
...
</plugins>			

Line 35 is the most important : it specifies the path where the exploded war is deployed in Jonas.
That configuration could work with another application server of course.