For the list of Windows Server 8 changes of interest to the IT Pro see:
Windows 8 for the IT Pro: The New Plumbing
To test all this stuff out, you will probably want to use the Windows 7 hardware you currently have.
This list is sourced from the blog post at:
http://blogs.msdn.com/b/b8/archive/2011/09/13/experiencing-windows-8-touch-on-windows-7-hardware.aspx listing machines that the touch-enabled features have been "tested" on, where "tested" = "works on my machine," and not "tested and supported by Microsoft,".
It is offered here so that early adopters can update it with additional hardware that runs the Windows 8 Developer Preview "on their machine". Feel free to add to the list, it is the wiki way!
You can find forum threads from other early adopters on both hardware and software issues at
http://social.msdn.microsoft.com/Forums/en-US/windowsdeveloperpreviewgeneral/threads . Find Windows 8 sample apps to run at:
You can also use the Windows 7 boot from VHD fetaure to try out Windows 8. Here's a how to blog post:
http://www.hanselman.com/blog/GuideToInstallingAndBootingWindows8DeveloperPreviewOffAVHDVirtualHardDisk.aspx. You may also want to check out
Dual Boot Windows 8 from VHD using Windows Setup.
Windows 7 machines that run Windows 8 (Developer Preview):