The February CTP (aka as the March CTP) is now available for download as a regular install and as a virtual PC. Here is a video that serves as an introduction to the CTP.
This CTP is a pre-release version of Visual Studio Orcas. This release features support for LINQ to SQL, which means you can use LINQ to query relational databases.
There were a few issues with this CTP when running on Vista, and when running side by side with Visual Studio 2005. As a result, if you have VS 2005 installed, or if you are running on Vista, then I would suggest using the VPC version of this download. When downloading the VPC version of Orcas, don't forget to get the base image.
Here is a link to various LINQ related articles and posts, and be sure also to see this post which details many of the changes since the May CTP. Here is a link to videos and articles that I have written on LINQ.
Here are some Anders videos from Tech Ed Barcelona:
Here are few other LINQ related videos to help you get started:
Here are some specs to review: