Two years ago we commissioned a white paper to examine approaches to uPortal - .LRN integration. His report can be found at:
http://web.mit.edu/~aessa/www/dotlrn/uportal/ Wickstrom's work is outdated but still useful as a reference point.
It's time to re-visit the issue. We think that OpenACS and .LRN will be attractive to a whole class of organizations if they are able to use uPortal as their portal framework and OpenACS/.LRN for collaboration and community applications.
I am starting this thread to track for exploring this issue.