This study, which is not new but was recently cited in the Department of Education meta-study of 2010, finds that students can benefit greatly from interactive video in online courses, if they are able to control the delivery. In other words, lecturettes or other content that is presented with play/pause/rewind/fast forward queueing, and scrollable and searchable text, are much more highly rated by students than static video or online courses without video. The interactive video-supported classes also received higher student outcomes. See the full study here:

“Instructional video in e-learning: Assessing the impact of interactive video on learning effectiveness”
Dongsong Zhang et al.

http://www.qou.edu/arabic/researchProgram/eLearningResearchs/instructional.pdf