North American Council for Online Learning:

New Research Reports Released on Online Learning:
Keeping Pace with K-12 Online Learning: A Review of State-level Policy and Practice by John Watson Released November 2006 [PDF]
An International Perspective of K-12 Online Learning: A Summary of the 2006 NACOL International Survey and International Matrix
Virtual Schools and 21st Century Skills, written by NACOL and the Partnership for 21st Century Skills (November 2006)
Learning Point/NCREL’s Synthesis of New Research on K-12 Online Learning
Exploring E-Learning Reforms for Michigan: the New Education (R)evolution

Corey Murray has more.