I'm sure this seemed like the right thing to do at the time. File a patent for a course management system when there is a TON of prior art that precedes your product or invention. Back in 2000, BlackBoard filed a patent for their Course Management System (CMS). They recently were awarded a patent. I'm not sure if the U.S. Patent Office is doing much research these days before awarding patents, but just digging around using Google dug up this information that points to a good deal of prior art: 
 
http://docs.moodle.org/en/Online_Learning_History 
 
http://www.downes.ca/cgi-bin/page.cgi?post=35237 
 
http://en.wikipedia.org/wiki/PLATO 
 
I'm sure that just like other proprietary software vendors who feel threatened by Open Source Software, BlackBoard sees the writing on the wall. Open Source software could potentially make them irrelevant. This is probably a reactionary move on their part in an attempt to stem the tide of customers who are leaving BlackBoard for CMS systems such as Drupal and Moodle. 
 
I find it VERY telling that as soon as the patent was granted, they filed a lawsuit against Desire2Learn. Had BlackBoard filed suit against IBM (who own their own CMS), they would probably have been in for a world of hurt. Going after a defenseless, small company like Desire2Learn says a great deal about the business philosophy of BlackBoard's management. While other companies have realized that innovation is the key to success, BlackBoard has decided that lawsuits are the answer. 
 
My best guess is that BlackBoard/WebCT stock is going to start diving in 12-24 months. Only time will tell. 
 
UPDATE: 
Anders Bylund recently (August 18) wrote in The Motley Fool: 
"Blackboard is an exciting company with a lot going for it, but until we see how its customers respond to the lawsuit situation, I wouldn't dare touch the stock with a 10-foot laser pointer. The fears might be overblown, but you just never know." 
CH