Blockbuster says it will begin stocking movies in high-definition DVDs in 1,450 stores beginning next month -- but only in the Blu-ray format. It currently stocks high-definition titles in about 250 stores in both the Blu-ray and HD DVD formats, but it said Sunday that more than 70 percent of its customers are renting the Blu-ray disks. In an interview with the Associated Press, Blockbuster merchandising exec Matthew Smith commented, "The consumers are sending us a message. I can't ignore what I'm seeing." The company said that it will continue to rent HD DVD titles in the stores that carry them now and also online.