The most obvious and common advantage of x64 is that the OS provides greater memory addressability. While most definitely true, this summary really does not do full justice to all the benefits provided by x64. It’s about more than just Memory - its also about Performance, Security, Compatibility and Community.
Was great fun talking about such a cool technology as x64 Extended Systems with so many users and people in the OEM channel. I mentioned this blog and that I would put up a few of the links I referred to in my presentation:
Join the Windows XP Professional x64 Edition Technology Advancement Program and "upgrade" your existing XP Pro license for a XP Pro x64 license for S&H. FAQ here.
I mentioned Star Wars: Episode III - Revenge of the Sith was rendered on AMD64 with Windows x64 too. Here are some links that talk about what JAK Films, a division of Lucasfilm got up to with Windows x64 (whilst still in beta!) on Opteron.
Another excellent resource is a new whitepaper - Benefits of Microsoft Windows x64 Editions - located at http://www.microsoft.com/windowsserver2003/techinfo/overview/x64benefits.mspx
Since you can't upgrade Windows XP Pro to XP Pro x64 because of the architecture change, one work around is the File & Settings Transfer Wizard which has just been updated to support this scenario: now supports gathering data from a 32-bit Windows XP environment and applying it in a 64-bit Windows XP environment.
Many exciting things happening in the x86-64 CPU space especially with Hardware Virtualisation - AMD "Pacifica" and Intel "Vanderpool" or VT. Microsoft has already annouced we will be shipping a Windows Hypervisor for these types of CPUs. Checkout out the PowerPoint slides from WinHEC 2005 on our Virtual Server: Overview and Roadmap
I also just notice that Intel have just annouced they are shipping the dual core Pentium D for desktops and AMD will be shipping the AMD Athlon 64 X2 Dual Core in a couple of days time (next month). Cool. I'm up for a buying a new PC for home in the next few months, wonder which way I'll buy...
UPDATE> checkout http://www.extended64.com/Article30.x64 for screenshots of a nic box. Windows Server 2003 Enterprise x64 Edition : eightway 16 cores with 128GB of RAM. More memory than disk space! Also http://www.theinquirer.net/?article=23518