Apple will launch its next-generation iPad on March 16, according to a new report. Citing a reliable Apple Store source, 9to5Mac reports that preparations are being made for a large Apple Store event culminating on Friday, March 16, which suggests that Apple plans to make the third-generation tablet available on that date. Apple is said to be planning two notable Apple Store openings for that day, and Verizon Wireless has also started teasing an upcoming…