According to sources, the power drawn from the Retina Displays combined with the thin and light form-factor of the MacBook Air may pose challenges for Apple and its product manufacturers. Because of this, a launch timeframe is unrealistic to pinpoint. While Apple is bringing USB 3 to the MacBook Pro, Apple seems to currently be undecided on whether or not to expand the new USB technology from their Pro line to the more consumer-oriented and affordable Air series.
Apple has been slowly adding High-DPI images to OS X in preparation for the updates.
