Microsoft SharePoint Server 2010 Beta is available for download now. You can download it from either of following links:

TechNet: http://technet.microsoft.com/en-us/evalcenter/ee388573.aspx

MSDN: http://msdn.microsoft.com/en-us/evalcenter/ee390819.aspx

 From the Microsoft Download Center 

SharePoint Foundation 2010 Beta

Microsoft Office Web Apps (Beta) the new web-based tools that extend the Microsoft Office 2010 experience to your browser

Microsoft FAST Search Server 2010 for SharePoint Internet Sites Beta for use with SharePoint Server 2010 for Internet Sites, Enterprise Edition

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