Yesterday, the long awaited Windows 7 Beta 1 was publicly available for download on Windows 7 official site. But due to high demand the links have been removed by Microsoft.
However you can still get the Windows7 Beta by visiting the direct download links with official ISO images below.
Windows 7 Beta Direct Download Links:
Windows 7 Beta 1 (x86)
Windows 7 Beta 1 (x64)
You can get the Windows 7 Beta product key below which works both for 32 bit & 64 bit.
Shared from Neowin.
Download your WINDOWS 7 BETA quickly because it is available for some time and certain number of copies only. Use a download manager to download your copy, as the Windows 7 Beta has an Image size of 3.2 GB
Update: The Official site of Windows 7 has been updated with the download links for 32-bit & 64-bit version. Please download your copy from there which is available in 4 languages.