Call of Duty: Black Ops 2 multiplayer stats won't be nuked back to nil when the game officially releases tomorrow. Treyarch game design director David Vonderhaar took to Twitter to say there won't be a reset at launch. So if you have an early copy your stats should be preserved come launch day, unless you're a "bad person doing bad things."
While there are undoubtedly those who've gotten hold of an early copy via unscrupulous means, there are going to be plenty of people who got one legitimately. Heck, Amazon is already sending out pre-ordered Wii U copies.