TUAW reports that it appears that the initiative is not just limited to assembly of new Macs, but will include investment in building many of the components on American soil as well

Apple won't be building all of those components, but will be investing money in US manufacturers to help them ramp up production for Apple and other companies. Some analysts scoffed at the announcement, saying it is only a public relations stunt that won't provide all that many jobs. But Cross Research analyst Shannon Cross said that wages and other costs for product assembly in China have risen sharply in past years, erasing much of the advantage of the Chinese plants. Cross also noted that building devices in the US mitigates the risk of intellectual property theft.

  Apple's US Mac production to go beyond assembly