I had not listened to Spirit's tune in quite some time. I had dinner with friends last night and decided to come home and give another listen. As a paralegal, I feel the suit will be dismissed. Just found the attached article....
http://www.forbes.com/sites/oliverherzfeld/2014/05/21/spirit-v-led-zeppelin-analysis-of-the-stairway-to-heaven-infringement-lawsuit/