You can now download Visual Studio Orcas Beta 1. Use one of the links found here:
If you are trying to decide which link to use, the main consideration for most people will be size. With the exception of the C# Express Edition, these downloads tend to have a hefty girth of approximately 5 GB. The Express Edition is much, much smaller. On the other hand, it has fewer features, but many developers will find it sifficient for their needs.
If you are upgrading from the 2006, May LINQ CTP, you might want to view this page, which shows which API's have changed since that time.
The LINQ samples for Beta 1 are also available for download. You will download an MSI which by default will install the samples as a zip file to your Program Files directory. A link will appear in your menu, and you can unzip the files to your Documents directory or some place where you have read/write permissions.