Wal-Mart has announced availability of what may be the first over-the-air (OTA) digital-to-analog converter boxes to hit the retail channel. Apparently 3,400 stores have stocked the $49.87 Magnavox STB and are ready for your $40 coupon (arriving as soon as next week). My concern is that the folks requesting the finite number of vouchers are all Engadget readers with ATSC-tuning HDTVs and/or satellite/cable service – making this a non-issue for them. Meanwhile, Grandma will be out of luck (or at least out some cash) next year when she realizes her rabbit-eared television no longer works and the coupons are long gone.