I surfed over to [phorum.org
] , and noted that they've moved from the Phorum 5 code from alpha status to beta status. This is good progress.
On the ISSS site, we should probably remain on the v3 code base until Phorum 5 has pass RC (release candidate) status, and had at least one maintenance release. There's not much point to our being on the bleeding edge, when we haven't maxed out the current version, yet.