I found this quote interesting:
The Internet Information Services 6.0 Web server featured in the OS has been enhanced with 64-bit support. This provides access to more memory and scalability for applications, Goldfarb said. "In high-performance scenarios, it's very, very important."
64-bit computing translates to needing fewer servers, requiring less management and lower licensing costs, Goldfarb said. Also included in Internet Information Services is a Web-security configuration wizard for setting security levels in Web applications.
Support for 64 bits in ASP.Net 2.0, meanwhile, has enabled MySpace.com, which runs a high-volume social networking portal, to consolidate operations from approximately 100 multiprocessor systems to 33 of these systems, said Aber Whitcomb, CTO at MySpace.com. The company has been using ASP.Net 2.0 with an earlier version of Windows.
"With 64-bit hardware, you can increase your memory footprint from 4GB on a single server to in our case, up to 16GB, but you can go a lot further than that," Whitcomb said. MySpace.com describes itself as the third most trafficked site on the Internet, with 11.5 billion page views in October alone.