I thought I'd wander over to PubMed and see if I could track down the research. Yep, but I can only get the Abstract, since I don't have a sub to Diabetes Care. Pah.
Seems it's not just glucose levels that it affects: After 40 days, all three levels of cinnamon reduced the mean fasting serum glucose (18-29%), triglyceride (23-30%), LDL cholesterol (7-27%), and total cholesterol (12-26%) levels; no significant changes were noted in the placebo groups. Changes in HDL cholesterol were not significant.
Sounds good to me! *runs off to make cinnamon toast* :D