Dimitris says:

following up on the discussions about AS branching:

a) the branch that produced AS 5.0.0.GA should be considered "dead". We won't be doing a dot release from this branch (5.0.1.CR1)
https://svn.jboss.org/repos/jbossas/branches/Branch_5_0/

b) trunk was instead branched into:
https://svn.jboss.org/repos/jbossas/branches/Branch_5_x/
The next AS release to fix 5.0.0 glitches and introduce any missing EAP features will be 5.1. As it is now the branch produces 5.1.0.Beta1 but I'm not clear yet if we have time for a Beta1 version; maybe we have to go directly to CR1.

c) trunk will produce the next AS6 release (6.0.0.Alpha1)
https://svn.jboss.org/repos/jbossas/trunk/
This is still WIP as to how exactly AS6 will look like, or if it will further broken out.