Microsoft has just released an updated version of Windows Vista to technical beta testers. Build 5456 is available in either x86 or x64 flavors right now on Microsoft Connect.
Neosmart just posted some additional information about this build:

"Some of the new features include a revamped Aero/DWM subsystem, and a completely overhauled and siginficantly less obtrusive UAP for all those that couldn’t stand the previous one. From what we have been told by Microsoft, the Time Zone bug that plagued previous builds of Windows Vista has been patched, and quite a few fixes in the Regional Settings and IME have been patched."

This is the first beta release o ... more

Install this update to fix application compatibility issues with Symantec Antivirus version 10.0.1.622. After you install this item, you may have to restart your computer.
Download:
English | MoreInfo & Other Language ... more

All the servers worldwide (Singapore, Redmond, California Server Farm, Dublin, and India) have been prepped and the public Beta 2 of Windows Vista is ready to download. There is no public release for Windows Server "Longhorn" as yet.
*PLEASE NOTE - These links may not be live just yet - so far the links are up and ready but the actual builds are not. Keep refreshing the page - should be live today*

Download here:
- (English x86)
http://download.windowsvista.com/preview/beta2/en/x86/download.htm - (English x64) ... more

The release is reportedly 5384.4, the same release given out at WinHEC 2006, to no ones surprise.
Get The key from microsoft for windows vista beta2 here
Use this link to download using the Download Manager (recommended)

Windows Vista Beta 2 x86 or x64
Direct Link: • Windows Vista Beta ... more

Windows Vista Beta 2 is now available for IT professionals and developers with MSDN and TechNet subscriptions. In the coming weeks, Microsoft will start the Windows Vista Customer Preview Program (CPP) for developers and IT professionals who are not members of the subscription services.

(This iso download from MSDN,Windows Vista Beta 2 Build 5384.4.)The Windows Vista CPP will also be available to technology enthusiasts that want to install and test a copy of Windows Vista Beta 2. You can get a head start on your Windows Vista CPP preparation by visiting the Get Ready ... more

At last, Vista Transformation Pack has finally come out! Despite the name Vista, you´ll get whole new update and more functions. Get the awesome Vista look today!
Vista Transformation Pack will give to your Windows XP system the new and cool look of Microsoft´s future operating system: Windows Vista. The pack changes most of the system icons, skins and toolbars and also adds new enhancements to your desktop such as a dock bar or a different system tray clock. Well, this is another very big update. In this release, you´ll get bunches of stuff you´ve never seen before in this pack such as Windows Media Player skins, WindowBlinds skin, new stuffs, etc. And bug ... more

The Windows Vista Upgrade Advisor is a small beta application that you can run on your current Windows XP-based computer to find out if it's ready for an upgrade to Windows Vista. When you run the Upgrade Advisor, it will scan your computer and generate an easy-to-understand report of any known system and device compatibility issues, along with recommendations on how you can get your PC ready for Windows Vista. Microsoft plans to add functionality to Upgrade Advisor, such as checking how your software applications will run with Windows Vista. Download the beta version today and check this site in a few months for a new version.
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Lead evaluations for new technologies and understand their impact on your IT environment and their potential for your company by pre-registering here. You will be notified first when the Windows Vista, Office 2007 and Exchange Server 2007 public beta releases become available. Additionally, you will receive updates and information regularly through the Microsoft TechNet Flash Newsletter, from the time you pre-register until the launch of the product.
http://www.microsoft.com/technet/prodtechnol/beta/preregister.mspx ... more

Microsoft has issued 32-bit and 64-bit versions of Windows Vista build 5381.1, which is a preview of the Beta 2 version of Vista the company intends to ship later this month to millions of users worldwide.
Windows users who are eager to test Windows Vista don't have much longer to wait: Microsoft will ship Beta 2 to millions of consumers sometime in late May. Currently, the company still plans to ship Beta 2 on May 22. Attendees of the Windows Hardware Engineering Conference (WinHEC) 2006, which runs May 23rd through the 25th, will receive Vista Beta 2 on DVD.
Seed Fixed!
Released By WinBeta.
Download:
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Vista Customization Pack is a tool to turn your Windows XP (with SP2) into Windows Vista. It basically changes the appearance and organisation of icons. However this tool doesn-t exactly to the real Vista theme.
Key features :
· New Installer offering 2 different setup options
· Full Installation
· Goodies (Aero Visual Style, Styler Toolbar themes, The WB Skin, Wallpaper)
· Language Independant · Dialogues are customized · IconCache rebuild · New System & Desktop Properties · New Wallpapers · Uninstaller [Revert your system easily] &mid ... more