Jamie Cansdale is a a pretty sharp guy. He's released the latest version of TestDriven.NET, one of the most productive addins for testing and debugging your code, and it works with Visual Studio 2005.
Not only does it work with the Pro versions of VS 2005, it also works with the Express versions of VB and C#. That's in spite of the fact the the Express versions don't support the ability to host add-ins :)
The clever dude figured out a way to "trick" VS 2005 into hosting his Add-in in Express, which is very cool, and will help lots of developers.
If you're planning to work with TD.NET with an express Version of Visual Studio, you should know theres a small caveat with it - the Code file must be "touched" first before the addin is available. Jamie has posted a specific movie showing exactly how to install and enable TD.NET in an Express edition. Watch the "How To" here.
You can download TD.NET from the main site, or through FolderShare.com, where Jamie is hosting the latest version directly (the main site requires registration, FolderShare does not)