"The Toshiba HD-D1 is an alternate design of the HD-A1 that is currently exclusive to Wal-Mart. Except for some slight cosmetic differences (the HD-D1 has an all-black finish and squared-off buttons, whereas the HD-A1 is half silver with circular buttons), the two products are identical; they even retail for the same $500 price. As such, the CNET hands-on review of the Toshiba HD-A1 covers the HD-D1 as well."
