Earlier today, Microsoft issued the latest version of their .Net framework. Version 3.5 SP1 is available now from the Microsoft Download Center and covers most existing platforms (XP, Vista, etc.).
Note: Installing Framework revisions can take some time, so allow be sure an allocate at least a half hour (or more) for your computer to download the necessary files and perform the update. The link is here.
Just a few moments ago, a separate language pack for the framework was also posted to the Microsoft Download Center.
In other tech news from MSFT, the latest August SDK for DirectX 9.0 c is now available.
(DirectX 10 continues to make progress for those with specific NVidia and ATI video cards).
Update 1 - Links corrected