Faced with the risk of losing its major competitive advantage, can Wal-Mart (NYSE: WMT) regain its reputation for rock-bottom prices? Restoring a slew of favorite items on its shelves sounds like a step in the right direction.

The discount retail giant is responding to a long stretch of lackluster sales figures and lost market share with an "It's Back" campaign. Wal-Mart cut many items from its shelves in the thick of the recession, in an effort to get lean, mean, and simplified. Now, it's restocking 8,500 of those banished goods, including fishing poles, fabric, and plus-sized fashions, according to Reuters. In its effort to cut costs, the company apparently started eliminating items customers actually wanted.

Wal-Mart's campaign, which will include TV advertising, will also inform shoppers that it matches rivals' prices. CNN Money recently reported that major rival Target (NYSE: TGT) offered lower prices on a sample of basic staple items, which certainly had to be a wake-up call for Wal-Mart.

The retail giant's flagging traffic implies defections in different directions. Higher-end shoppers probably gravitated to discounters like Target and Costco (Nasdaq: COST), while many less-well-heeled shoppers likely grabbed rock-bottom deals at so-called dollar stores like Dollar General or Family Dollar (NYSE: FDO).

Beyond Wal-Mart's usual competitors, shoppers can now find excellent deals on items at Amazon.com (Nasdaq: AMZN) and Overstock.com (Nasdaq: OSTK), in addition to bricks-and-mortar contenders like Big Lots (NYSE: BIG). That doesn't necessarily make all of these companies good stock buys right now, but they could collectively weigh on Wal-Mart's future as a decent long-term investment.

Despite Wal-Mart's negative reputation in some quarters (labor issues, Mom-and-Pop-shop-killer rep, major contributor to suburban sprawl, etc.), it always had the siren song of low prices to hold shoppers' interest. In this strangely precarious economic climate for the company, its shrewd effort to regain its footing may prove easier said than done, since the Bentonville Behemoth's immense scale doesn't exactly make it a nimble enterprise. I won't consider Wal-Mart an appealing stock idea until it shows solid signs of regaining its basic competitive advantage --  preferably in the form of better sales.

Would you buy Wal-Mart now and hold it for the long haul? Or should existing shareholders hurry up and sell, and move onto greener, more growth-oriented pastures? Let us know in the comments box below.