In this specific case (Seam 3.0), there is no current production support so for now it seems like it may be ok to work directly from svn trunk (minus the broken build problem when bugs are committed).  However, I have been involved in private JIRAs via the Redhat/JBoss CSP in the past (with SLAs of course) and that means the core devs will need access to a clean, working trunk for prod maintenance, bug fixes, etc.  So I'd imagine in the future there will be a trunk and another future project branch at minimum.  It must have been like this in the past?

btw, from this link: http://anonsvn.jboss.org/repos/seam/modules/ I don't see a core module.  The Seam 2.2.x core will be heavily refactored (or completely re-written/replaced) by Weld 1.0.x I'd imagine.  But will it really be completely replaced?  I can't imagine so if Seam3 will be backwards compatible with Seam 2.x apps...  I'd like to try out Seam 3 eventually with our non-trivial Seam/RF/JPA/JSF app here (which consists of two Maven projects and a couple of common/infrustructural projects that are shared b/n projects here).

I'm also wondering how backwards-compatible JSF 2 is.  I tried it briefly with my app and experienced some problems (possibly due to misconfiguration?) so reverted back to JSF 1.2 Mojarra for now.  It's tough to sell Java EE 6 at enterprise shops that tend to be conservative in terms of adopting technology (e.g. we like to stay 1 to 2 major revisions behind).  thx.