From lightning-fast delivery for online shoppers to mega-size stores with wine bars, restaurants and taxidermy displays, the future of retail is taking shape in Tampa Bay. Walmart Stores Inc. on Monday took a direct shot at Amazon.com , announcing that it too will host a massive online sale Wednesday - the same day Amazon had pegged as a sort of "Black Friday in July" for members of Amazon Prime, which costs $99 a year for two-day shipping.