Simply put, the news means you'll be able to buy your upgrade or new computer pre-loaded with Windows 8 in October. The operating system will be released to manufacturing in August, which is when certain enterprise business customers will be able to upgrade.
Of course, if you're in urgent need of a new computer, there's no need to wait for October. If you buy a Windows 7 PC now, you'll be eligible to upgrade for $15; those who bought a PC that runs Windows 7, Vista, or XP prior to June 2012 will be able to upgrade for $40. If you really can't wait, the Windows 8 Release Preview is available for download right now. Just be sure your computer ispowerful enough to run it, first.