Check out the bikeradar info on the new Di2 Ultegra coming later this year. Also check out Ultegra options for CX bikes.
http://www.bikeradar.com/news/article/shimano-ultegra-di2-first-look-30616
http://www.bikeradar.com/news/article/shimano-ultegra-di2-first-look-30616