Fairly well integrated with .LRN, the biggest challenge is to finish upgrade scripts for Oracle and PG. I did a bunch of work on this around October but not recently, I've been working on other things.
The portal rewrite has been used in the GP CTX project, and at least one other commercial project as well, standalone OpenACS. The GP CTX project added localization for the user-visible pages.
I've let it sit in part since it's taken us so long to finalize the OpenACS 5.1 series (we're just about to release OpenACS 5.1.5, which will be the last of this series, we finished Oracle testing today).
Portal has been developed under our CVS HEAD (not OpenACS 5.1) that will release as OpenACS 5.2 in late March or sometime in April, and I would anticipate integrating the portal rewrite with whichever .LRN version is released on top of 5.2.
In the interim people asked me to work on speeding up the template list builder/paginator, the forums package, and bugtracker (if you've noticed that openacs.org forums are much faster than they were six months ago, it's largely due to work I did in December).
.LRN will benefit from the forums and list builder/pagination speed-ups (Galileo has added pagination to parts of .LRN, I know).