One of our partners - AppointLink did a nice job customizing SharePoint at Yale Law School. Essentially they were able to replace Backboard LMS with SharePoint functionality. This may not supplant all of your LMS needs but in many cases its good enough (and way cheaper).
Here are some LMS SharePoint videos/demos:
1600 S. Brentwood Blvd. Suite 220
Brentwood, MO 63144