Heh ... I've been having the same thoughts regarding Mac OS X, too ... you don't need Mac OS X server to run OpenACS, whether you're using Oracle or PostgreSQL, both run fine on Mac OS X "consumer".
The reason to get server is to get the server admin tools but for a K-12 ".LRN in a box" Mac distro there's no reason to require it.
Now a Knoppix CD with OpenACS pre-installed and running on port 80 would be tres cool, too ... as well as one with .LRN, I guess ... would get us past the hump of "this is so hard to try out most people never get there" ...
RedHat's moves have astonished me. Just a personal comment.
