Finally after Microsoft announce of the Windows7 Beta release to the public updated the Windows7 Download page with the message. Thanks for your interest in the Windows 7 Beta. The volume has been phenomenal—we're in the process of adding more servers to handle the demand. We're sorry for the delay and we'll re-post the Beta as soon as we can ensure a quality download experience.
Microsoft servers experionced a high volume of traffic and site was extreamly slow and sometimes down due to this. It seems like there is a high interest for the Windows7.
