I've posted up the class library that I have written against the Myspace REST API's. You access and read more information about it on http://www.codeplex.com/myspacetoolkit.
Download it, check it out and discuss it and let me know what you think. Additionally, feel free to send me a message if you would like to join on as a developer for the project.
I see this project continue to evolve along with the MDP. Currently, I haven't implemented any parsing routines for the responses, but I will be doing this shortly. I just wanted to get this out there as quickly as possible to allow for other .NET developers to access the functionality.
Please remember that this is pretty beta and I am sure that there will be exceptions that occur.
To read more information go to: http://www.joedeveloper.net/blog/post/MyspaceToolkit.aspx