Log in with your account to Customer portal

https://access.redhat.com/

and then

https://access.redhat.com/jbossnetwork/restricted/listSoftware.html?downloadType=distributions&product=appplatform&productChanged=yes

If you are looking for the community bits, download AS 5.1 from here

http://www.jboss.org/jbossas/downloads

You can get an evaluation version for free:

http://www.jboss.com/products/platforms/application

Regards,

/Daniel