Summaries of in-depth product reviews on Paul Thurrott's SuperSite for Windows
http://www.winsupersite.com

Windows Server 2003 x64 Editions
Contact: Microsoft * 800-426-9400
Web: http://www.microsoft.com
Price: $500
Summary
Pros: Identical functionality to the 32-bit versions of Windows Server 2003; huge memory- and resource-allocation improvements; seamless migration
Cons: Some application-incompatibility problems
Rating: 4 out of 5
Recommendation:
Windows 2003 Standard x64 Edition, Windows 2003 x64 Enterprise Edition, and Windows 2003 x64 Datacenter Edition are basically identical to the corresponding 32-bit versions of Windows 2003 with Service Pack 1 (SP1) but support a whopping 1TB of RAM. They offer a compelling middle ground between the 32-bit x86 and Itanium versions. Expect x64 to become the mainstream server platform by mid-2006.
Full Review: http://www.winsupersite.com/article/reviews/windows-server-2003-x64-editions-preview.aspx

Microsoft Internet Explorer 7.0 (Preview)
Contact: Microsoft * 800-426-9400
Web: http://www.microsoft.com
Price: $500
Summary
Pros: Free; features extensive security updates and new features
Cons: Available only for Windows Server 2003 and Windows XP (32-bit and x64 editions)
Rating: 4 out of 5
Recommendation:
Designed primarily to mitigate IE-based electronic attacks, IE 7.0 will include major security enhancements, including antiphishing technologies, IP traffic-encryption facilities, and user-requested features such as tabbed browsing and better support for Web-standard Cascading Style Sheets (CSS) features. IE 7.0 won't be available to Windows 2000 customers, however. IE 7.0 is due in late 2005.
Full Review: http://www.winsupersite.com/article/reviews/internet-explorer-7-preview.aspx