Looks like a firm order for 75 CS100's, with entrance to the fleet slated for 2018. Also means no E190's...
http://www.prnewswire.com/news-releases/delta-orders-state-of-the-art-fuel-efficient-bombardier-c-series-300259092.html
http://www.prnewswire.com/news-releases/delta-orders-state-of-the-art-fuel-efficient-bombardier-c-series-300259092.html