Yes, your application can be done with seam.
You require jboss 4.2 jdk 5 and and on the development environment. Of cource you can use an integrated any in the IDE so that you don't need to call ant from cmd.
On server you only need a running jboss (to run jboss you need jdk 1.5)
ant not needed. Yoy can easy copy the ear and datasource in the jboss deploy directory.
You could also use tomcat if you don;t want to use a real jee environment.
A war file is not enough if you want to create a "normal" jee5 application. You will neeed a ear (having a war inside).
Do you or some one who has successfully make examples under seams-2.0.0.GA work under tomcat6 or 5.5 (without embedded JBoss AS) as instructed in each example readme.txt wish to share your how-to?.
I have tried to use both ant 1.6.5 amd 1.7 in combination with jdk 1.5 and 1.6. The jpa example (and others) successfully compiled for the .war file. But the deployment to tomcat get an error due to SeamListener. I am still learning and investigating. It is even better if you have it under maven. Thanks for sharing.
See the post "Seam 2.0.0.GA jpa failed in tomcat6" and its answer.
Take a look at here:
I used Tomcat 5.5 but it should work with Tomcat 6 (just note common/lib directory).
Hope this helps