Michael: "Ultimately, .LRN will likely occupy the space between Moodle, which is ideal for small schools with few development resources and lots of grassroots energy, and Sakai, which will theoretically be ideal for very large schools with significant development resources and a need for a tool that plays well with lots of other pieces of their enterprise pie."
I wouldn't yet discount .LRN playing in the enterprise arena. For example, Valencia has 20,000 users and growing to 40,000. We also now are beginning to have a strong integration story. We have written a web services based interface to DSpace, which is being adapted --- even as we speak --- as a repository for learning objects at MIT. There is an external authentication module. We have internationalization. And we also expect to have a connector that works with registrar systems.
If you want to drive an SUV, go for Sakai (whenever it comes out).
The most important thing about OpenACS/.LRN is that it follows an open source development methodology. Sakai is closed source development. I will put my money on OpenACS/.LRN.
