CHARLOTTE, NC (WBTV)- Wal-Mart employees in the Charlotte region are preparing for what could be the busiest shopping day ever. The store will open at 8pm on Thanksgiving night and offer three waves of Black Friday deals. The most popular time may be Thursday night from 10 to 11pm, when the retailer is offering an unprecedented guarantee on three hot-ticket items including an iPad 2 with a $75...