The kids over at Tech Arp got their hands on a draft of Microsoft's Windows 7 upgrade scheme. According to the the document, titled "The Microsoft Windows 7 Upgrade Program Rev. 2.1," Vista machines purchased from participating vendors after July 1st will be eligible for an upgrade to the new OS, whenever it comes out -- in a similar manner to the XP - Vista switchover. The idea here is to forestall a sales slump in the lead up to the new OS release. Upgrades will be tier-for-tier, with Vista Home Premium users getting to switch up to Windows 7 Home Premium when the time is right, Vista Business to Windows 7 Professional, and Vista Ultimate users getting an upgrade to Windows 7 Ultimate. Additionally,
