Wal-Mart's not alone in getting aggressive on prices for flat-panel plasma, LCD and HD TVs. According to the Consumer Electronics Association, high-definition-TV prices have dropped almost 23 percent from last year as retailers' inventory expands.

Most analysts don't think Best Buy, Circuit City and other electronics sellers have much to fear from Wal-Mart's TV discounts because Wal-Mart doesn't carry the same depth of name-brand TVs as these other retailers. Moreover, some consumers are complaining that they can't find these discounted items in Wal-Mart's stores or on its Web site.

Wal-Mart recently slashed the price for a 42-inch HD plasma TVs by about $500. A Panasonic model was listed as "out of stock" on walmart.com but the site encouraged consumers to consider similar items. One consumer wrote to CNNMoney.com "Is this a bait-and-switch?" Wal-Mart didn't immediately return phone calls for comment.