Preview at WWDC likely in June, followed by September launch.
Apple Pulls 'Genius' TV Ads from YouTube and Apple.com
Apple stopped airing the ads on television soon after they were introduced during the Opening Ceremonies of the Olympics, with Apple's ad agency saying they "were intended only for a 'first run' during the Olympics". They remained on YouTube and Apple's website for several weeks, and only in the past several days were they removed entirely.
Apple does tend to remove older advertisements from its website and YouTube over time, but the company still has ads on YouTube from as far back as November 2010.