Yes you heard correctly - The long anticipated release of Windows Vista SP1 is here. Currently you can download it from the Microsoft Download Center and it will be pushed via Windows Update in April.

Things to know before you download Windows Vista SP1...
http://technet.microsoft.com/en-us/windowsvista/bb968859.aspx

  • Windows Vista SP1 is available in English, French, German, Spanish, and Japanese. Other languages will be made available soon.
  • Microsoft strongly recommends using Windows Update to download and install Windows Vista SP1 on single PCs:
    • The download size from Windows Update of Windows Vista SP1 for x86 is 65 MB (compared to 450 MB from the Microsoft Download Center).
    • The download size from Windows Update of Windows Vista SP1 for x64 is 125 MB (compared to 745 MB from the Microsoft Download Center).
  • Windows Update will recognize PCs with known problematic drivers and postpone downloading Windows Vista SP1 until the PC has updated drivers or other applicable updates. Using Windows Update will help ensure you have the most trouble-free update experience possible.

    Some Windows Vista users may encounter an issue with a small set of hardware devices that may not function properly after updating a Windows Vista PC to Windows Vista SP1.   This is an issue with the way the device drivers were re-installed during the Windows Vista SP1 update process, not with the drivers themselves-these drivers worked on Windows Vista RTM and they work on Windows Vista SP1.  This problem is typically corrected by simply uninstalling and reinstalling the driver. We are working with the manufacturers of these devices to get the known problematic drivers and their install programs updated, and also on other solutions we can use to ensure a smooth customer experience when updating to Windows Vista SP1 using Windows Update. For new PCs provisioned with Windows Vista SP1, this is not an issue.

    If you choose to install Windows Vista SP1 via the standalone installer available on the Microsoft Download Center, Microsoft advises that you first visit Windows Update and install all optional drivers. Read Knowledge Base Articles 948187 and 948343 for more information.

    If you have a prior version of the Windows Vista SP1 beta installed, you must uninstall it prior to installing the final version. Use the Control Panel applet "Programs and Features" and select "View installed updates" from the top left of the task pane. Under Windows, look for "Service Pack for Windows (KB936330).

935791: How to obtain the latest Windows Vista service pack:
http://support.microsoft.com/kb/935791

32-bit
http://www.microsoft.com/downloads/info.aspx?na=22&p=43&SrcDisplayLang=en&SrcCategoryId=&SrcFamilyId=&u=%2fdownloads%2fdetails.aspx%3fFamilyID%3db0c7136d-5ebb-413b-89c9-cb3d06d12674%26DisplayLang%3den

64-bit
http://www.microsoft.com/downloads/info.aspx?na=22&p=42&SrcDisplayLang=en&SrcCategoryId=&SrcFamilyId=&u=%2fdownloads%2fdetails.aspx%3fFamilyID%3d874a414b-32b2-41cc-bd8b-d71eda5ec07c%26DisplayLang%3den

Here are some links to general information on the improvements in Vista SP1.

Overview of Windows Vista Service Pack 1
http://www.microsoft.com/downloads/details.aspx?FamilyId=39B802EA-B2CF-4585-8CEA-2CC6A6247CB3&displaylang=en
This white paper presents an overview of Windows Vista SP1 and the improvements it contains.

Notable Changes in Windows Vista Service Pack 1
http://www.microsoft.com/downloads/details.aspx?FamilyID=d69c4e1b-c81a-41be-b1f5-66e615ba5912&DisplayLang=en
This document provides more detail about the notable changes made to Windows Vista in Service Pack 1, which were focused on addressing specific reliability, performance, and compatibility issues, supporting new types of hardware, and adding support for several emerging standards.

Release Notes for Windows Vista Service Pack 1
http://www.microsoft.com/downloads/details.aspx?FamilyID=b5b681f5-f366-4ad2-ba10-6a7d209de7bd&DisplayLang=en
Release documentation that contains known issues for Windows Vista Service Pack 1 (SP1).

Hotfixes and security updates included in Windows Vista Service Pack 1
This document contains a list of all the hotfixes and security updates included in Windows Vista SP1.

Windows Vista SP1 Guides for IT Professionals
http://technet2.microsoft.com/WindowsVista/en/library/90a564b9-34af-4a6b-937f-324e1862244b1033.mspx
These guides will assist IT Professionals in evaluating and deploying Windows Vista SP1 and are downloadable versions of the SP1 guides found in the Windows Vista Technical Library.

Windows Vista SP1 Frequently Asked Questions
http://technet.microsoft.com/en-us/windowsvista/bb738089.aspx