These links aren't live *yet* but will be soon...

Install Internet Explorer 8

Internet Explorer 8 can be installed on Microsoft Windows Vista^® Service Pack 1 (SP1), Windows Vista, Windows XP^® Service Pack 2 (SP2), Windows Server^® 2008 and Windows Server2003 Service Pack 2 (SP2). Downloads are available from the following locations:

Internet Explorer 8 Beta 1 for Windows Vista and Windows Server 2008 

Internet Explorer 8 Beta 1 for Windows Vista x64 Edition and Windows Server 2008 x64 Edition

Internet Explorer 8 Beta 1 for Window XP SP2

Internet Explorer 8 Beta 1 for Windows Server 2003 SP2

Internet Explorer 8 Beta 1 for Windows Server 2003 SP2 x64 Edition and Windows XP SP2 Pro x64 Edition

Related:  Welcome to Internet Explorer 8 Beta 1

UPDATE: The downloads just went live Enjoy!